HK1028691B - System and method for broadband millimeter wave data communication - Google Patents

Description

System and method for broadband millimeter wave data communication

Technical Field

The present invention relates to wideband radio frequency communication systems and methods, and more particularly to systems and methods for providing wideband communication of information between processor-based systems via a centralized communication array.

Background

In the past, the communication of information between processor-based systems separated by significant physical distances, such as Local Area Networks (LANs) and other general purpose computers, has been an obstacle to the integration of such systems. The options available to bridge the physical separation between such systems are not only limited, but also require undesirable compromises in cost, performance and reliability.

A set of historically available communication options includes such solutions: a standard Public Switched Telephone Network (PSTN) or multiplexed signal is used over the existing physical link to bridge the span and provide information communication between systems. While such solutions are typically inexpensive to implement, they include a number of undesirable characteristics. In particular, because these existing links are typically not designed for high-speed data communications, they lack the bandwidth to quickly transfer large amounts of data. As LAN speeds increase to 100Mbps in buildings, local PSTN voice band circuits represent an even more significant point of inhibition for broadband metropolitan area access, and thus become less and less desirable alternatives. Furthermore, such connections lack the fault tolerance or reliability found in systems designed for reliable transmission of important processor-based system information.

Another historically available set of communication options is available at the opposite end of the price range than those mentioned above. This group includes such solutions: using a fiber optic ring or point-to-point microwave communication. These solutions are typically prohibitively expensive for all but large users. Point-to-point systems require a dedicated system at each end of the communication link and cannot spread the costs of such systems across multiple users. Even though these systems may be modified to be point-to-multipoint, enabling economy of use of multiple systems for some system components, today's point-to-point microwave systems are not capable of providing broadband data services, but instead provide traditional bearer services, such as: t1 and DS 3. In addition, these systems typically provide a proprietary interface and are therefore not well suited for simple interfacing with a variety of general purpose processor-based systems.

While a fiber optic ring provides economy if utilized by multiple systems, it must be physically connected to such systems. The cost of placing and maintaining such rings is significant due to purchase, even though the economics of multi-system utilization often cannot overcome the realized over-pricing.

Disclosure of Invention

There is therefore a need in the art of information communication for a communication system that provides cost effective bridging of large physical distances between processor-based systems.

There is also a need in the art for a communication system that provides high speed, broadband information communication between processor-based systems.

There is also a need in the art for a fault tolerant communication system that provides reliable bridging of physical separation between processor-based systems.

In addition, there is a need in the art for a broadband communication system that provides simple connectivity for a variety of processor-based systems and communication protocols, including general purpose computer systems and their standard communication protocols.

These and other objects, which will be apparent to those skilled in the art, are achieved in communications systems and methods which require the use of the communications devices or nodes of the present invention, wherein a communications array or hub is centralized to provide an air link between physically separate processor-based systems, or other communications sources, such as voice communications. Preferably, the central array may be based on an information communication physically connected to the system providing communication between the over-the-air link and the physically linked system. Furthermore, a plurality of such systems may be used to bridge the physical separation of large systems through intercommunication of multiple central arrays. Furthermore, by arranging a plurality of such communication arrays to provide a cell-like overlapping pattern, universal surface coverage may be provided.

In a preferred embodiment, the central communication array includes a plurality of individual antenna elements in Time Division Multiplexed (TDM) communication with a processor-based system. This system processes the signals received at each antenna element in order to transmit them to their desired destination. An advantage of using a plurality of individual antenna elements at a central communications array is that only antenna elements having a radiating pattern covering a remote site (subscriber) requiring communications traffic need be implemented at any particular time. Thereafter, additional antenna elements may be installed as more users demand services through a particular hub. Modular expansion of the service capabilities of the hub results in a reduction in initial installation costs where only a few users initially request service while maintaining the flexibility of implementation of omni-directional and/or cellular overlay communication coverage not possible with point-to-point systems.

Also in a preferred embodiment, the communications spectrum utilized by the communications system is Frequency Division Multiplexed (FDM) to provide multiple users with multiple channels for simultaneous communication of information. In addition to simultaneous communication of information to users, FDM channels may also be used to communicate control information to network elements over predetermined frequency bands concurrently with the transmission of other data.

Preferably the present invention uses carrier frequencies in the millimeter wavelength spectrum, such as 10 to 60 GHz. Such a carrier frequency is desirable in order to provide a communication bandwidth sufficient to transmit at least 30Mbps through each defined FDM channel of about 10 MHz.

FDM channels can provide full duplex by defining a transmit (Tx) and receive (Rx) channel pair to serve one user as a single Frequency Division Duplex (FDD) channel. However, it will be appreciated that providing full duplex by FDD comes at the cost of consuming the available spectrum at an increased rate, since traffic to a single user actually requires dual channels.

In addition to multiplexing communications over frequency division channels, time division multiplexing may be utilized to provide multiple simultaneous-looking communications over a single FDM channel. Where one of the FDM channels is decomposed into a predetermined number of discrete time slices (burst periods) in the form of one frame. Each burst period may be used by a different user such that information traffic having many TDM bursts contained in a single frame is directed to/from many users on a single FDM channel.

Also, full duplex can be synthesized on a single FDM channel of Time Division Duplex (TDD) by using a burst period similar to that used in TDM. With TDD, Tx and Rx frames, each frame having one or more burst periods is defined to provide communication in a particular direction at a predefined time.

It should be appreciated that any of the above FDM, FDD, TDM, and TDD schemes, or the like, may be used in any combination deemed advantageous. For example, a single frequency division channel may be time division multiplexed to provide communication to many users, while simultaneously time division duplexed to synthesize full duplex communication with these users.

In the embodiments described above, the communication system may utilize an initialization algorithm, perhaps including a token passing arrangement for shared data users, to poll the users' systems and determine the communication attributes of each such system at each antenna element of the central array. This information can be used to determine the optimal resource allocation, including antenna elements, TDM burst periods, FDD frequency allocations, and TDD Tx and Rx time allocations for each such system. This information may additionally be used to provide additional resource allocation to maintain system integrity in the event of an anomaly, thereby providing system fault tolerance.

The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.

Drawings

For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates the interconnection of a processor-based system of a preferred embodiment of the present invention;

FIG. 2A illustrates an isometric view of a centralized communication array of a preferred embodiment of the present invention;

FIG. 2B illustrates a horizontal plane cross-sectional view of the centralized communication array depicted in FIG. 2A;

FIG. 2C illustrates a vertical plane cross-sectional view of the centralized communication array depicted in FIG. 2A;

FIG. 3A illustrates an embodiment of the signal components transmitted by the present invention during a time division multiple access burst period;

FIG. 3B illustrates an embodiment of the signal components transmitted by the present invention during a time division duplex burst period;

FIG. 4 illustrates an embodiment of a node of the present invention;

FIG. 5 illustrates one embodiment of an initialization algorithm used in configuring communications between a centralized communications array and nodes of the present invention;

FIG. 6 illustrates the interconnection of a processor-based system through the hub network of the present invention; and

fig. 7-8 illustrate a preferred embodiment of the various components of the hub of the present invention.

Detailed Description

The present invention provides high speed data communication over a broadband air interface that allows data access between systems of remotely located users. Referring to fig. 1, it can be seen that such wireless communication may be used, for example, to provide high-speed bridging of physical separation between multiple processor-based systems, as illustrated by system 100. The processor-based system may include a Local Area Network (LAN), such as: LANs 110 and 120, or separate computer systems, such as: a PC 130. It should be understood that a processor-based system utilizing the present invention may be a general purpose computer, stand alone and interconnected, such as by a LAN. In addition, the system may be connected to other communication systems, such as: voice or video in conjunction with or instead of communications originating from the processor-based system mentioned above.

The system bridged by the present invention can communicate with a centralized communication device, also referred to herein as a "hub", using a communication device, referred to herein below as a "node". Still referring to fig. 1, the hub is shown as unit 101 and several nodes are shown as units 150, 151 and 152 connected to LANs 110 and 120 and to PC 130.

Also, as shown in FIG. 1, such wireless communications may be used to provide high-speed communications between a processor-based system having one node connected thereto and a communications backbone, such as backbone 160, through hub 101. It should be appreciated that backbone 160 may be any form of communication device physically connected to hub 101, such as a broadband fiber optic gateway or other broadband data-level connection, a T1 communication line, a cable communication system, the internet, and the like. Also, multiple backbones, such as that illustrated by backbone 160, can be used to interconnect multiple hubs to a communication network.

A communication network comprising a plurality of hubs is shown in fig. 6. Through such a network, a node in direct communication with one hub, such as hub 101, such as node 150, may communicate with a node in direct communication with another hub, such as hub 620, such as node 621. Such communication may be accomplished through two hubs interconnected via, for example, a backbone 160. Of course, it should be understood that intercommunication between hubs may be accomplished through an over-the-air inter-range communication between two hubs, such as hubs 101 and 630, through an information "backhaul". It should be understood that a communication network may include many hubs that communicate with other hubs through such means as over-the-air connections or direct backbone interconnections, etc. Information communicated from a node in direct communication with a hub may be sent over a plurality of such interconnections to a node in direct communication with any hub of the communication network.

In a preferred embodiment, the hub of the present invention is an omnidirectional antenna array having a plurality of individual antenna elements. One such separate antenna element is shown as antenna element 200 in fig. 2A. The antenna element is a narrow beam directional antenna with a predetermined communication lobe. The antenna elements are arranged in an array to provide an omni-directional composite radiation pattern. It should be understood, however, that only the number of antenna elements required to communicate with a predetermined number of remote systems may be used instead of an omni-directional configuration, if desired.

Preferably, antenna elements including hub 101, such as antenna element 200, provide directional reception at Extremely High Frequencies (EHF), such as 38GHz, which provides millimeter wave (mmWave) communication in the Q-band. Such frequencies are advantageous because they have small wavelengths, which is desirable for highly directional antenna communications. Moreover, antennas used for such frequency communications may be physically small while providing large signal gain.

The combination of such a highly directional antenna with high gain improves the frequency reuse and reduces the likelihood of multipath interference. In addition, the high gain achieved by such antennas must allow communication over a reasonable distance, such as three (3) miles, from the point-to-point of the antenna while using reasonable power levels.

Furthermore, such frequencies have only recently been licensed by the U.S. government for use in radio communications. As a result, this frequency range is currently not commonly used by other communication technologies. It should be understood, however, that the advantages of the present invention may be realized by utilizing any frequency band that provides the ability to transmit data at high speeds, provided that the selected band produces at least one channel of about 10 MHz.

In the preferred embodiment, with omni-directional coverage of the hub 101, the individual antenna elements are arranged azimuthally to cover a full 360 degree radius in the horizontal plane, as shown in fig. 2B. It will be appreciated that arranging the antenna elements in this manner may provide a radio communications coverage layer covering radially around the hub 101 by selecting the communication lobe of each antenna element so as to provide coverage in areas where adjacent antenna elements do not provide coverage.

Of course, as discussed above, increasing the number of sufficient antenna elements to provide a full 360 degree radial pattern may be accomplished modularly depending on the system usage requirements. It will be appreciated that the modular nature of the individual antenna elements provides an economical means of providing initially limited coverage to a region of development even though 360 degrees of coverage is required. For example, only a few locations or users wishing to communicate with the present invention within the geographic area covered by a particular hub site, only a hub is established that includes those antenna elements necessary to service those users. Thereafter, when additional subscribers require service within the hub service area, additional antenna elements may be added to the hub to provide service to their associated nodes. Eventually the hub can be filled with individual antenna elements to enable communication in a full 360 degree radius around the hub.

The hub of the invention, which can be extended to include further antenna elements, can be implemented in many ways. For example, a hub frame adapted to receive individual antenna elements at predetermined locations may be initially established. Thereafter, individual antenna elements may be attached to this hub frame at locations corresponding to areas requiring service or increased density of service.

Similarly, a hub rod and motherboard or other support structure may be initially established. When the area served by the hub requires service or increased service density, a separate antenna element structure may be added to the hub support structure. In this embodiment, each antenna element includes its own support and mounting structure to connect it to the hub support structure and any adjacent antenna element structures. It will be appreciated that such an embodiment reduces start-up costs, where only a few antenna elements are required to start serving the area. Furthermore, such an embodiment provides greater flexibility in locating individual antenna elements, as the antenna elements are not limited to being located as dictated by a preexisting frame structure.

Preferably, 360 degree communication around the hub 101 is achieved with a total of 22 individual antenna elements, a communication lobe having a horizontal (azimuthal) beam width of approximately 16 degrees and a vertical beam height of 2.5 degrees. However, depending on individual design constraints, such as: the presence of reflected waves and their associated multipath interference may utilize any number of individual cells. Additionally, as discussed above, only as many antenna elements as are needed to communicate with certain identification nodes 150 are used, if desired.

Experiments have shown that it is advantageous to use antenna elements with a beamwidth of the 16 degree level in the hub and the cell overlap map providing channel reuse for each hub in providing the desired channel reuse. For example, it has been found that antenna elements operating in the millimeter wave spectrum with about a 16 degree beam configuration as described above have side lobe characteristics that allow the same channel to be reused at antenna elements located at the same hub radially displaced by about 90 degrees.

Still referring to fig. 2B, it can be seen that each antenna element 200 of the preferred embodiment comprises a horn 210 and a module 220. In the preferred embodiment, using EHF, the horn 210 is a mixed mode lens correction horn, providing approximately 32dB of gain. Module 220 is a composite millimeter wave front end module that receives and transmits 38GHz radio frequency energy converted to/from an Intermediate Frequency (IF), such as in the 400 and 500MHz range, for communication with a modem (modem), such as modem240 shown in fig. 2C, via the horn 210. Of course, the components of the antenna element may differ from those described above, depending on the carrier frequency used. Likewise, the horn and module properties of the antenna elements may be different from those described above, e.g. requiring different carrier frequencies or beam patterns.

Preferably, the modem240 is a 42Mbps throughput broadband modem using Quadrature Amplitude Modulation (QAM). As discussed below, the system may utilize a variable rate modem, such as is commercially available from various manufacturers, including Broad Com, Philips, and VLSI technologies. Such variable rate modems provide for transmission of variable information density (i.e., many bits per symbol) at a fixed baud rate, such as 8.5Mbaud, for example, from 17 to 51Mbps (corresponding to 4QAM, encoding two bits per symbol, up to 256QAM, encoding 8 bits per symbol). Typically such modems utilize matched data filtering, producing a bandwidth occupying the radio frequency, i.e. 15% to 30% over the theoretical nyquist bandwidth. Variable modems are useful in increasing spectral efficiency by varying the density of information delivered to users of the service according to communication attributes such as their relative distance from the hub.

For example, increased data density in a particular time frame may be communicated to a node geographically located near a hub by using 256QAM, using the same occupied radio frequency bandwidth and the same transmitter power as using 4QAM to transmit a signal having reduced data density to a node geographically located at the edge of the hub radiation pattern. Because of the reduced effect of signal attenuation, and therefore the higher signal-to-noise ratio associated with a given power level, near nodes compared to far nodes, it is partially achieved that the data density is increased to near nodes without requiring a greater increase in power transmission. The higher signal-to-noise ratio experienced at the proximate nodes typically maintains increased information density. However, regardless of the transmission density ultimately addressed, it may be advantageous to initially synchronize the system using a lower order modulation for a given node and then going to a higher order modulation when using a variable rate modem.

Link management information, such as control signals to adjust the information density described above and/or error correction information, may be multiplexed as control information transmitted into the data stream by the modem. For example, the control information may include multiplexing filtering and error correction information, such as Forward Error Correction (FEC) data embedded in the data stream. Of course, many methods of providing link management and error detection/correction can be provided by multiplexing the data streams transmitted by the modems of the present invention with information.

In a preferred embodiment, the individual antenna elements are arranged in a number of columns. The columns may be just an identification set of antenna elements or may be a physically delineated arrangement of antenna elements. Regardless of their physical interrelationship, a column of antenna elements includes a number of antenna elements having substantially non-overlapping radiation patterns. An embodiment of an antenna element comprising three vertical columns is shown in fig. 2C. The hubs 101 of each column are preferably arranged to provide substantially the same far-end field radiation pattern. However, different columns of antenna elements are preferably adapted to provide simultaneous communication in one channel or multiple channels, unlike antenna elements having overlapping radiation patterns. For example, a first column of antenna elements may be communicated by utilizing a first frequency band, while a second column of antenna elements may be communicated by utilizing a second frequency band. Similarly, the antenna elements of the first column, although using the same channel setting as the antenna elements of the second column, are transmitted over a particular channel of the setting, while the antenna elements of the second column are transmitted over a different channel. The use of these different frequencies provides a convenient means by which additional communication capacity can be served to a defined geographical region.

Of course, the hub is fully scalable and may include many columns, different than that shown. A number of columns comprising a number of antenna elements may be utilized by the present invention. For example, a single column of antenna elements may be used to provide omni-directional communication from hub 101, where increased communication density is not required. Similarly, two columns, each column comprising only a single antenna element, may be used to provide increased capacity in a limited area defined by the radiation pattern of the antenna element.

Also, a subsequent addition of columns to the hub may be implemented, as discussed above with respect to the addition of individual antenna elements. For example, it has been determined that a hub comprising any combination of columns is insufficient to provide the required communication density, and antenna elements comprising many additional columns may be added. Of course, only a particular portion served by the hub area requires increased communication density, and the added column may include only those antenna elements having a radiation pattern covering the particular portion that requires increased communication density, if desired.

Alternatively, the columns of antenna elements may be arranged to provide different radio communication coverage areas around the hub 101. Such differences in radio communication coverage may be achieved, for example, by adjusting different columns to have different numbers of "down tilts" with respect to the vertical axis. The down-tilting of the columns may be achieved by physical tilting of individual antenna elements or by many beam steering techniques known in the art. In addition, the adjustment of the down tilt may be made periodically, such as dynamically during antenna operation by including a mechanical adjustment or beam steering technique as described above.

In addition, antenna elements having different radiation pattern properties may be used to provide the defined radio communication coverage range discussed above. For example, an antenna element for providing communication in an area close to one hub may provide a radiation pattern with a wide beam and thus a lower gain than the preferred embodiment of the antenna element described above. Likewise, an antenna element for providing communication in an area further away from the hub may provide a radiation pattern with a narrow beam and thus a higher gain.

Where the antenna elements of one column have different downtilts or radiation patterns, the individual columns may be used to provide coverage patterns that form concentric circumferences, the combination providing substantially uninterrupted coverage around a predefined area around the hub 101. Of course, only individual antenna elements may be adjusted to have a different down tilt or radiation pattern than other antenna elements of the column or hub. Either arrangement may be used to provide substantially uniform communication coverage, e.g., there are geographical cells that interfere with the respective radiation patterns. Likewise, this alternative embodiment may be used to compensate for many near/far related communication anomalies.

As can be seen in fig. 2C, the hub 101 comprises an outdoor unit (ODU) controller 230 connected to each individual antenna element 200. The ODU controller 230 is connected to a radio frequency modem240 and an indoor unit (IDU) controller 250. Although separate connections are shown from ODU controller 230 to modem240 and CPU260, it should be understood that communication between ODU controller 230 and IDU controller 250 may be accomplished through path connections of modem240 to ODU controller and CPU 260. Similarly, control information regarding the operation of the ODU controller 230 may be generated by the modem240 instead of the CPU260, and thus communicated through the connection between the ODU controller 230 and the modem 240.

The ODU controller 230 includes circuitry adapted to enable the individual antenna elements of the hub 101 to communicate with the radio frequency modem240 at appropriate intervals in order to transmit or receive the required signals. In one embodiment, ODU controller 230 includes time-division digital control switches that operate in synchronization with the burst period defined by IDU controller 250. Preferably, IDU controller 250 provides gating pulses to the switches of ODU controller 230 to provide switching synchronized with the burst period defined by IDU controller 250. It will be appreciated that simple integration into the antenna array is provided at very low cost using such switches. However, any conversion means that is synchronizable with the burst period defined by the IDU controller 250 may be used if desired.

Operation of ODU controller 230 results in each individual antenna element communicating with IDU controller 250 in a predetermined communication sequence timed manner, i.e., frames of a burst period. This in turn results in each individual antenna element communicating with the modem240 within the IDU controller 250. It will be appreciated that such conversion results in Time Division Multiplexing (TDM) of each antenna element to the modem 240.

Of course, the single antenna element provides bi-directional communication, and a second connection between ODU controller 230 and the respective antenna element may be provided, such as shown in fig. 8. Such connections may be used to provide synchronization to circuitry within the antenna element, such as by strobing as discussed above, to select between transmitting or receiving circuitry at the appropriate frame and/or burst period. By selecting the combined transmit and receive circuitry to be switched with the ODU controller 230, the antenna element may be connected to the modem240 to provide two-way communication through the modem, under appropriate circumstances, resulting in Time Division Duplexing (TDD), as described in detail below with respect to the best mode for carrying out the invention.

Also, or in the alternative, the connection between the antenna element and ODU230 may be used for other control functions in addition to controlling the TDD conversion of the antenna element. For example, a control signal connected in this way may be used to dynamically adjust an antenna element for a particular determined frequency to be suitable for communication with the communication device at a particular burst period of a frame. In the preferred embodiment, control signals are provided by CPU810 to tuners, such as up/down converters 892 and 893 internal to antenna module 220, as shown in fig. 8. Such control signals may be provided by the control processor to program phase-locked loop circuits within the various antenna modules, or synthesizer hardware, to select particular frequencies for transmitting and/or receiving communications. Likewise, a control signal may be provided to adjust the amplitude of the transmitted or received signal. For example, tuners 892 and/or 893 may include adjustable amplification/attenuation circuits under control of such control signals. It will be appreciated that the two control functions described above result in a method whereby individual antenna elements can be dynamically configured to communicate with nodes of the system.

IDU controller 250 includes a processor labeled CPU260, electronic memory labeled RAM270, and a router labeled interface/router 280. Stored in RAM270 is a switching instruction algorithm that provides switching instructions or synchronization to ODU controller 230. Buffering information communicated through modem240 or interface/router 280 can also be provided by RAM 270. Similarly, RAM270 may also contain additional stored information, such as antenna element association tables, link management information, initialization instructions, modem configuration instructions, power control instructions, error correction algorithms, and other operational instructions discussed further below.

Although a single modem is depicted in fig. 2C, it should be understood that the hub system of the present invention is fully scalable to include many modems, depending on the information communication capacity required by the hub. Please note that fig. 7, the IDU controller of the present invention adapted for TDD communication is shown to include two modems.

Modems 240 and 700 of fig. 7 are similarly configured to include burst mode controllers 720 and 721, QAM modulators 730 and 731, QAM demodulators 710 and 711, and channel direction control circuitry, represented as TDD switches 740 and 741. However, it should be understood that the burst-mode controller 721 is synchronized with the main burst-mode controller 720 and the synchronization channel modulator 760. Synchronization of the burst-mode controller, which is represented as a control signal provided by the main burst-mode controller 720, provides a means by which the burst period of the modem and the TDMA conversion of such communication frames and individual antenna elements can be fully synchronized. In the preferred embodiment, the synchronous clock is from interface/router 280 and is derived from the bit stream by master burst mode controller 720. Of course, synchronization may not be achieved using means of control signals provided by the master burst mode controller, such as: if desired, an internal or external clock source is used. One advantage of the synchronization of the various components of the hub is that the transmission and reception of each individual antenna element is limited at a predefined period which allows for greater reuse of the channel as discussed in detail with respect to the best mode for carrying out the invention.

It should be appreciated that synchronization channel modulator 760 provides a means by which the burst mode controller timing information is modulated for provision to ODU controller 230. It should be understood that in the preferred embodiment where CPU260 provides control signals to the ODU for the control functions discussed above, synchronization channel modulator 760 may also include a MUX761 that provides a multiplexed signal to modulator 762.

Preferably the signals of the various modems of the hub are superimposed on different carrier frequencies such as IF1 of modem240 and IF2 of modem 700. Similarly, the synchronization channel modulator 760 superimposes a control signal including burst mode timing information and control functions on an appropriate IF. These separate signals can then be easily combined by splitter/combiner 750 and delivered to ODU controller 230 through a single coupling. The same IF may of course be used as a carrier by the modems of the hub, for example IF multiple connections or one multiplexer connection is maintained between IDU controller 250 and ODU controller 230.

It should be appreciated that adding capacity by adding multiple modems to the IDU controller 250 requires circuitry in the ODU controller 230 in addition to the switch allowing TDMA access to a single data stream of one modem as discussed above. Attention is now directed to fig. 8, wherein ODU controller circuitry corresponding to a plurality of modems contained within IDU controller 250 is shown.

It should be appreciated that switches 870 and 871 and signal splitters/combiners 880, 881 and 882 in combination with synchronizer 830 accomplish TDMA conversion as previously described with respect to the antenna elements of the individual modems as described with reference to utilizing a single modem. Also shown in communication with CPU810 is a synchronization channel modulator 860 for demodulating burst mode control signals and various other control signals provided by the ODU over the single connection shown. In the preferred embodiment where control signals are passed from the IDU controller to the ODU controller, the sync channel modulator includes a MUX861 in combination with a demodulator 862, providing control information to CPU810 and timing information to synchronization device 830. Of course, where multiple connections are used between ODUs and IDUs, synchronization channel modulator 860 may be omitted.

Switches 870 and 871 are adapted to provide selection of the different data streams provided by each modem, tuning a common intermediate frequency to the antenna element via tuners 840 and 841. In a preferred embodiment, the modules 220 of the antenna element are adapted to receive intermediate frequencies and convert them for transmission at a desired frequency through the horn 210, as discussed above. In a preferred embodiment, module 220 is adapted to receive a single IF. Accordingly, ODU controller 230 includes tuners 840 and 841 for adjusting respective intermediate frequencies IF1 and IF2 of different modems to a common intermediate frequency IFa. It should be understood that although a single bi-directional tuner for each IF is shown, a separate tuner for the transmit and receive signal paths, connected to the bi-directional signal path by a TDD switch, may be used IF desired. Such an arrangement is discussed in detail below with respect to the antenna module 220.

Although tuned to a common frequency, the signals from the modems are physically separated and switched to an appropriate antenna element by switches 870 and 871 through signal combiners 880, 881 and 882 under control of synchronizer 830. It should be understood that by controlling switches 870 and 871, any sequence of burst periods from any modem can be transmitted by any antenna element.

Although the selection of a particular modem modulated signal has been discussed with reference to switching under the control of a synchronizer circuit, it should be understood that this function can be accomplished by many means. For example, the module 220 may be adapted to receive respective intermediate frequencies. A variable tuner in block 220 may be used to select a signal modulated by a particular modem from the combined signal using a programmable phase-locked loop circuit, such as by tuning to a particular intermediate frequency under the control of CPU810 and synchronizer circuit 830. Of course, tuners are used to distinguish between the various signals modulated by the modems, tuners 840 and 841 and switches 870 and 871, if desired, and signal combiners 880, 881 and 882 may be eliminated.

It will be appreciated that the use of short burst periods, such as on the order of microseconds, requires such variable tuners to tune to the required frequency and reach steady state quickly in order to avoid severe signal distortion. In line with this, experiments have shown that it is advantageous to use the above-mentioned switching matrix in the selection of the individual signals to be provided in the desired burst period.

In a preferred embodiment, each antenna element is adapted for bidirectional communication. Thus, each antenna module 220 may include TDD switches 890 and 891 connected to the synchronization device 830, as shown with respect to antenna element 200, to provide synchronized switching of the antenna elements during transmit and receive frames.

Furthermore, as it is contemplated that the radio frequency of the transmission of the system is different from the frequency of the IF used in the various components of the communication system, each antenna module 220 may also include a tuner to up-convert and/or down-convert the IF to the required radio frequency RF for radio communication. The tuners for up-converting and down-converting the signal are represented in fig. 8 as an up-converter 892 and a down-converter 893. It should be understood that although one transducer is shown for both the transmit and receive signal paths within the antenna module 220, a single bidirectional transducer may be used if desired. Of course, where a bidirectional converter is used, TDD switches 890 and 891 may be eliminated, resulting in a configuration as discussed above with respect to IF tuners 840 and 841.

It will be appreciated that a series of converters may be used to perform up-conversion and/or down-conversion of the signal. For example, in a preferred embodiment, using an intermediate frequency of 400-500MHz and a radio frequency of about 38GHz, a single stage converter up-converts or down-converts between frequencies requiring significant signal filtering to distinguish between the various sidebands generated very close to the frequency of interest. Thus, the signal is preferably up-converted and/or down-converted in each stage, such as by an intermediate frequency of 3 GHz. Thus in the preferred embodiment, converters 892 and 893 comprise multi-stage converters that up-convert or down-convert signals between 400 and 500MHz, 3GHz and 38 GHz.

It will be appreciated that an intermediate frequency close to the radio frequency may be utilised and therefore no precise filtering of the converted signal and the multi-stage conversion described above are required. However, it should be appreciated that it is generally more economical to manufacture switch matrices suitable for lower frequencies than for higher frequencies. Thus, in a preferred embodiment, an intermediate frequency is utilized which is substantially lower than the transmitted radio frequency.

In a preferred embodiment, EHF radio is used to separate the available spectrum into discrete channels for Frequency Division Multiplexing (FDM). Where 38GHz is used, for example, the available spectrum may be a 1.4GHz spectrum between 38.6GHz and 40.0 GHz. This 1.4GHz spectrum may advantageously be subdivided into 14 channels of 100MHz each. Of course, as discussed below with respect to the best mode for carrying out the invention, other divisions of the available frequency spectrum may be employed to provide sufficient signal bandwidth to carry the required information.

To allow full duplex use of FDD as discussed above, a single 100MHz channel can also be subdivided into a pair of 50MHz channels, thus defining a 50MHz transmit (Tx) channel and a 50MHz receive (Rx) channel. Of course, each 100MHz channel may be used entirely as a Tx or Rx channel, if desired. Those skilled in the art will appreciate that utilizing the full 100MHz spectrum of a channel results in a half-duplex channel, since no spectrum is maintained within that channel to allow information to be communicated in reverse. However, as discussed below with respect to this best mode, full duplex can be combined on any single channel by utilizing TDD to provide Tx and Rx frames within that channel.

Each Tx and Rx channel may similarly be divided into 5 discrete sub-channels of 10MHz each, resulting in frequency division multiplexing of the 50MHz Tx and Rx channels. Due to the above-mentioned TDMA per antenna element, each channel is divided into predetermined TDMA time slots. These TDMA time slots may be further broken down into protocol time slots; a protocol slot is a sufficient time for transmitting a packet of a format to a predetermined protocol. For example, each 10MHz subchannel may utilize 64QAM to transmit three 10Mbps Ethernet data packets in a 250 μ sec TDMA slot. Alternatively, these subchannels may be used to provide different data throughputs, such as a 10Mbps Ethernet data packet in a 250 μ sec frame using Quadrature Phase Shift Keying (QPSK). Each Tx and Rx channel can be used as a single channel spanning the full 50MHz bandwidth, if desired, without frequency division.

Fig. 3A shows an example of a 30Mbps sub-channel communication formatted as three ethernet data packets per TDMA time slot. The 250 musec frame contains a control header 300 followed by a guard time sync field 301. The synchronization field 301 is followed by a 10mbps lan data packet 302 and forward error correction data 303, which itself is followed by a guard time synchronization field 304. The synchronization field 304 is similarly followed by a 10Mbps LAN data packet 305 and forward error correction data 306 and a guard time synchronization field 307. The synchronization field 307 is followed by a 10mbps lan data packet 308 and forward error correction data 309, which is also followed by a guard time synchronization field 310. It should be understood that this example of a 30Mbps communication is one embodiment of one signal component within a single channel of the present invention. There are countless ways by which to utilize the spectrum disclosed above for communication. It should be understood that any such method may be used in accordance with the present invention.

In addition to information communication between processor-based systems through hub 101, control functions may also be communicated between hub 101 and node 150. An example of such control communications is shown in fig. 3A as control header 300. Alternatively, the control function may be transmitted over a predetermined channel or sub-channel of the FDM spectrum. These control functions may include requesting retransmission of data packets, requesting adjustment of transmission signals, TDM timing information, amplitude of instructions to adjust modulation density or dynamic allocation of hub resources. The use of such control functions is discussed in more detail below.

Information transmitted to IDU controller 250 via antenna elements may be retransmitted by hub 101 through a backbone, such as backbone 160 shown in fig. 6, and ultimately to other processor-based systems. It should be understood that a plurality of such backbone communication devices may be connected to a single hub 101.

Alternatively, information transmitted to IDU controller 250 may be redirected by hub 101 through preselected antenna elements and ultimately received by another processor-based system when switched to communicate with controller 250. Directing attention to fig. 6, this communication path is shown, for example, by network 110 communicating through hub 101 to network 120.

A large geographic distance between two communication processor based systems may be bridged with multiple hubs. For example, as provided in fig. 6, hubs 101 and 630 communicate over an air link through the antenna elements. The two hubs may provide information communication between any combination of processor-based systems in communication with either hub.

It should be understood that the information received by IDU controller 250 of hub 101 may be retransmitted in a variety of ways. In one embodiment, IDU controller 250 correlates the communication or its associated burst period with a predetermined communication path through a particular antenna element 200, as dictated by the control of ODU controller 230. In this manner, fig. 2C represents communications received by IDU controller 250 at antenna element 200b, e.g., may be transmitted by IDU controller 250 through antenna element 200b, as indicated in RAM270 by an associated table or the like. Such a correlation table or other relevant information may be used by IDU controller 250 to convey any communications received over a particular unit, burst cycle or channel of hub 101 including a backbone, to another particular unit, burst cycle or channel of hub 101. Such an embodiment is efficient, for example a processor-based system communicating with hub 101 via antenna element 200a would only want to communicate with a processor-based system communicating with hub 101 via unit 200 b.

However, when a processor-based system wishes to communicate with multiple different processor-based systems via hub 101, or a single antenna element is used by multiple processor-based systems, the correlation table described above may be invalid. Thus, in the preferred embodiment, the information communicated through hub 101 includes routing information. Such information is preferably in the form of data packets conforming to the Open Systems Interconnection (OSI) model. An example of OSI routing information that may be used in this embodiment is the Transmission Control Protocol (TCP) standard. It should be understood, however, that any routing information indicating the destination of a received data packet, whether or not in compliance with the OSI standard, can be utilized by the present invention if desired.

It should be understood that modem240 modulates and demodulates communications between the antenna elements and IDU controller 250. Thus, radio frequency communications received at any antenna element may be stored as digital information in RAM 270. Interface/router 280 may utilize a predetermined piece of information contained within the digital information, such as may be stored in RAM270, to determine routing of received communications. In a preferred embodiment, the routing information is provided by the network layer of data packets conforming to the OSI model. Such information is contained, for example, in each LAN data packet shown in fig. 3.

This digital information may be redirected by the hub 101 through the backbone 160 or through the antenna elements via the modem when appropriate routing is determined using the information contained within the transmitted information. It should be appreciated that because TDMA is utilized, this digital information may be stored in RAM270 until such time as ODU controller 230 determines from the routing information when to couple the correct antenna element to IDU controller 250, thus providing the necessary routing for communication.

Having described the hub 101 of the present invention in detail, attention is now directed to FIG. 4, wherein node 150 is more fully shown. In the preferred embodiment, the node 150 contains two main components, an outdoor unit 410 and an indoor unit 450, as depicted in FIG. 4.

The outdoor unit 410 includes an antenna 420, a module 430 and a modem 440. Where EHF is used, antenna 420 is preferably a dish antenna providing approximately 42dB of gain with a communication lobe of approximately 2 degrees. The module 430 is similar to the module 220 discussed above, and receives and transmits a 38GHz radio frequency converted to an IF in the range of 400-500MHz via the antenna 420 for communication with the RF modem 440. Preferably, module 430 includes various tuners and TDD switching components shown in fig. 8 with respect to module 220. However, it should be understood that many component configurations are possible that are suitable for use in module 430, as are they in module 220. It should be understood that the link shown between the CPU460 and the module 430 may provide a signal that controls the synchronous switching of the TDD switch according to the TDD frame of the associated hub. Modem 440 may be a variable rate modem having a fixed baud rate with a variable bit density per symbol corresponding to the use of the variable rate modem at the associated hub. Of course the antenna and module properties of node 150 may be different than those described above, e.g. requiring different carrier frequencies or beam patterns.

The indoor unit 450 includes a CPU460, a RAM470, and an interface 480. It should be understood that the indoor unit 450 and the outdoor unit 410 are connected such that information received by the antenna 420 as RF energy is transmitted to the indoor unit 450.

Interface 480 provides data communication between indoor unit 450 and node 150, and a processor-based system, such as LAN490 shown in fig. 4. In addition, interface 480 formats the data communication to be compatible with the processor-based system so connected. By way of example, LAN490 is coupled to node 150 and interface 480 may send and receive ethernet data packets, LAN490 utilizing an ethernet compatible communication protocol. However, it may be advantageous for interface 480 to provide an asynchronous receive/transmit protocol, in which node 150 is connected to a single computer. Those skilled in the art will appreciate that interface 480 may comprise multiple communication protocols in a single embodiment, be user selectable, or may be included in a single module within controller 450 as desired.

RAM470 is connected to both interface 480 and CPU 460. Where TDM is used at hub 101, RAM470 may store information received at node 150 through interface 480 while waiting to be transmitted to hub 101. RAM470 may also contain additional stored information such as initialization instructions and link management information such as modem configuration instructions, power control instructions, and error correction instructions discussed in detail below.

Having described the hub 101 and node 150 of the present invention in detail, the interaction of these elements will now be described. As discussed above, RAM270 of hub 101 and RAM470 of node 150 may include instructions for the operation of CPUs 260 and 460, respectively. These instructions may include, for example, methods of programming hub 101 and node 150 for communication and methods of link management including communication error correction.

In addition, both RAM270 and RAM470 may temporarily store information communicated through the device for retransmission in the event of a detected transmission error. Transmission errors may be detected by CPUs 260 and 460 in various ways. One such method known in the art is to transmit error detection information with the transmitted data packet. Such a method is defined in the data link layer of the OSI model described above.

Attention is directed to fig. 3A and 3B, wherein each of the three illustrated data packets includes associated Forward Error Correction (FEC) information. It should be understood that the FEC information may include a summary (summary) indication of the associated data packet content by such means as a checksum parity indication, or the like. This general indication may be generated by the sending CPU, CPU260 or 460, or may be incorporated into a particular transport protocol utilized by the processor-based system, for example, as a data packet conforming to the ethernet protocol. Regardless of its origin, this information can be used to detect errors in the transmitted data and then correct the errors, such as by requesting retransmission of valid data packets.

As discussed above, both RAM270 and RAM470 store information communicated in a form readable by CPUs 260 and 460, respectively. Accordingly, the CPUs 260 and 460 can utilize predetermined pieces of information of digital information contained in the RAM270 and the RAM470, respectively, in order to detect a communication error. For example, in the embodiment shown in fig. 3A, the receiving CPU may generate a summary indication of the contents of each LAN data packet stored in RAM and compare this summary indication with the associated FEC information. When a difference between the two generalized indications is determined, the receiving CPU may request retransmission of the LAN data packet by the sending CPU.

However, in a preferred embodiment, the FEC information includes data redundancy in the data stream using a particular encoder. When detecting transmission errors, a decoder available at the receiving site can be used to provide partial error correction of the data stream. Such error correction from the encoded redundant data can correct the transmitted information until a predetermined percentage of errors in the transmission. Preferably, the FEC information so utilized is a block code such as: Reed-Solomon FEC protocol.

For example, in the embodiment shown in fig. 3B, the receiving CPU may decode the information carried in the FEC data packets and compare this information with the contents of each ATM data packet stored in RAM. When a transmission error is detected by such a comparison, the receiving CPU can correct the ATM data packet using the redundancy data encoded in the FEC data packet. Of course, the transmission of data packets serves beyond the correction of the encoded redundancy data using FEC data packets, and retransmission of data packets may be used if desired.

As previously discussed, predetermined sub-bands of the communication channel may be used to convey control functions such as: the above-mentioned retransmission request or other control functions, such as: power level adjustment and information density adjustment. Alternatively, a control function may be included in each TDMA burst transmission, for example as a control header 300 as shown in fig. 3A or a control channel block 363 as shown in fig. 3B. For example, the corresponding CPU will detect a request for retransmission and a LAN data packet response with a retransmission request existing in a predetermined control function sub-band or control header.

Of course, the above-described method of error correction may be omitted if desired, if the information is transmitted without errors or if error correction of the transmitted information is handled by another device. Further, the storage of the communication information in RAM270 and RAM470 may be omitted if TDM is not utilized and error correction of the retransmitted information is not required.

The preferred embodiment also includes a link maintenance algorithm that monitors communication parameters, such as errors in communications, associated with a particular node 150 in the hub's RAM 270. Upon determining that there are unacceptable communication parameters, such as an unacceptable error rate determined by comparison to a predetermined acceptable error rate, CPU260 may transmit an instruction to the particular node to make the appropriate adjustment. For example, CPU260 may instruct node 150 to adjust the communication transmission power to achieve an acceptable error rate or to adjust the M-ary QAM signal level at which information is transmitted (i.e., to adjust the number of bits per symbol, hereinafter referred to as the QAM rate). Of course, CPU260 may also provide such control signals to the respective QAM modulators associated with the hub, resulting in appropriate modulation/demodulation of the signals transmitted to the node. As described above, these control functions related to link maintenance may be communicated between CPU260 and CPU460 using designated control function sub-bands or control headers.

When a control command is detected to coordinate communication, CPU460 provides the necessary commands to the appropriate components. For example, as discussed above with respect to the hub, CPU460 may cause module 430 to adjust the transmit power or may cause modem 440 to adjust the QAM rate, depending on the attribute role or control information transmitted by the hub.

For example, control signals may be provided by the CPU460 to a tuner within the antenna module 430. Such control signals may be provided by a control processor for programming phase-locked loop circuitry within the antenna module or synthesizer hardware to select a particular frequency for transmitting and/or receiving transmitted information. Likewise, a control signal may be provided to adjust the amplitude of the transmitted or received signal. For example, tuners within module 430, such as those illustrated as module 220 of FIG. 8, may include amplification/attenuation circuitry under control of such control signals. In response to determining the node at the hub, adjustments to these attributes and the information density of the communicated data may be made by the node and communicated over the control channel or may be made by an algorithm at the node. It will be appreciated that some adjustment of attributes by the node may require a corresponding adjustment at the hub, such as an adjustment of QAM rate or channel. Thus, in such a situation the node may communicate control functions to the hub.

It should be appreciated that periodic adjustment of communication parameters may be necessary even though, as discussed in detail below, an initialization algorithm has been used to properly initialize such communication parameters because of the presence of allergies affecting communications. For example, although the initial QAM rate and/or transmission power level may be selected when communication is initiated, various environmental conditions, such as rain, may cause severe signal degradation. It is therefore advantageous to monitor communication parameters in order to provide an adjustment to the occurrence of such allergy compensation. It should be appreciated that communication of the monitoring and control functions of the communication parameters may be from a node to a hub where such a node has detected unacceptable communication attributes.

In addition to storing communication information and associated link maintenance algorithms, RAM470 is used in the preferred embodiment to store instructions used by CPU460 at operational node 150. Such instructions may include channels in the available spectrum that are not used by node 150, since TDM and synchronization information may be used for the communication windows communicated between node 150 and hub 101, such as: frame timing and propagation delay offsets, allowing TDM and/or TDD communications. In addition, RAM470 may also store instructions used by CPU460 to dynamically allocate hub resources, such as the above-mentioned channels or burst cycles available for communication and communication windows, as discussed below.

It should be understood that although in the preferred embodiment the antenna elements of hub 101 and antennas 420 of nodes 150 are pre-selected to use narrow beams, the environment in which the present invention may be utilized may include physical topologies that cause reflections of the transmitted signals. Such reflections tend to cause multipath interference in communications between node 150 and hub 101. Thus, RAM470 includes an initialization algorithm as part of the communication instructions mentioned above. Of course, such an initialization algorithm may be stored in a processor-based system in communication with node 150 to achieve the same result, if desired.

The initialization algorithm operates with a similar algorithm stored in the hub 101. Just as with the initialization algorithm of node 150, the initialization algorithm used by hub 101 may also be stored in a processor-based system in communication with hub 101 to achieve the same result. The initialization algorithm at hub 101 operates to cause node 150 to transmit a predetermined signal in the available spectrum to allow mapping of communication parameters such as the strength of the signal received at each antenna element of hub 101. This information may be used by the present invention to determine the individual antenna elements best suited for communication between node 150 and hub 101. This in turn determines the timing of the communication window or burst period available to the node 150 based on the TDM of these antenna elements. This timing information may be stored in RAM470 allowing CPU460 to time transfer through antenna 410 to obtain synchronization with the antenna element switching by ODU controller 230. Of course, it may not be advantageous to utilize such an initialization algorithm, for example, when multipath and co-channel interference are not involved. Thus, the use of such an initialization algorithm may be omitted if desired.

In addition, multiple nodes communicate with hub 101, and co-channel interference may result from communicating between several nodes. Thus, the initialization algorithm discussed above is fired (initialized) at each such node, and hub 101 may store communication parameters for each node. Hub 101 may then determine the likelihood of co-channel interference between several nodes 150 and define a subset of the available spectrum for each such node 150 to communicate to, i.e., assign a different channel or burst period to each such node 150. In addition, this information may be used to dynamically allocate hub resources for a particular node. In the case of use by a first node, such dynamic allocation may involve temporarily allocating a burst period or channel previously assigned to the first node to another such node.

The communication parameter information for each node may be used to determine the initial QAM rate available to the variable modem, as discussed above, to be used for a particular node. The initial QAM rate determination may be based on a particular signal strength that provides an appropriate carrier-to-noise (C/N) ratio for a particular QAM rate. For example, a C/N ratio of 11 dB (BER 10) has been found^-6) Is sufficient to support a 4QAM modulation. Similarly, a C/N ratio of 21.5 db (BER 10) has been found^-6) Sufficient to support modulation of 64 QAM.

Of course, since signal strength degrades with distance, QAM rate determination may alternatively be made by measuring the propagation delay of the transmitted signal, and thus the distance from the hub to the node. In a preferred embodiment, the propagation delay, and therefore the distance between a node and the hub, is determined by the node initially synchronizing to the frame timing established by the hub. Thereafter, the node transmits a shortened burst during a predetermined time slot. This transmitted burst is offset from the hub frame timing by the propagation delay time. The hub uses this offset to calculate the propagation delay and hence the distance from the hub associated with the transmitting node. Thereafter, a particular propagation delay or distance may be associated with the selection of a particular QAM rate for the node.

Regardless of how the determination is made, the selection of the maximum QAM rate for a particular node allows for more efficient use of the available spectrum by increasing the information density to those nodes having appropriate communication properties. Such increased information density is possible, for example, for nodes located close to the hub without increasing the transmit power of nodes located far away from the hub as compared to less intensive information communication.

Attention is now directed to fig. 5, wherein a preferred embodiment of the initialization algorithm of hub 101 is shown. Although a single iteration of the initialization procedure is shown, it should be understood that the initialization procedure may be repeated for each node in communication with hub 101, establishing a data set reflecting the communication attributes of each node relative to hub 101.

An antenna element counter N is initialized at step 501. It should be appreciated that the antenna element counter N may be used by an initialization procedure to refer to the number N of individual antenna elements of the antenna array comprising the hub 101. Thereafter, in step 502, the antenna element counter N is incremented by 1.

In step 503, the initialization program transmits a control signal via the antenna element N requesting a node to transmit a predetermined sampling signal. It should be understood that the control signal is transmitted directly to a predetermined node. The node may be selected from a data set of known nodes in communication with the hub 101, or may be selected by an operator from a node input such as a control signal, or may be determined from a response to a polling signal broadcast from the hub 101.

The initialization program monitors the antenna element N during a predetermined time in step 504. It will be appreciated that the amount of time to monitor the antenna elements is predetermined to be an appropriate amount of time for the signal from the node sufficient to cause multipath interference to be received. In the preferred embodiment, the predetermined amount of time to monitor the antenna elements is the time required for one complete TDM cycle through all N antenna elements of hub 101.

It is determined in step 505 whether the predetermined sampled signal was received by the antenna element N within a predetermined monitoring time. If no such sampled signal is received, it assumes that antenna element N is not in communication with the node seeking initialization information. Thus, the initialization routine proceeds to step 509 to determine whether all antenna elements have been monitored. If negative, the process returns to step 502 and increments the antenna element indicator to monitor for additional antenna elements.

It will be appreciated that the transmission of the control signal and the subsequent monitoring of one sampled signal may be repeated at a single antenna element N. By statistically analyzing the multiple results, repeated iterations at the antenna element N may be used to provide more accurate sampling, thus ignoring or reducing the effects of irregularities caused by the surrogate factors.

If a sampled signal is detected at the antenna element N, however, the initialization routine continues to step 506 and determines the propagation delay of the transmission of the signal from the node. It will be appreciated that by knowing the time of transmission of the control signal from antenna element N and the time of reception of the sampled signal at antenna element N, the initialization procedure can determine the propagation delay of the signal transmitted from the node to hub 101. In addition, to increase the accuracy of this determination, the initialization program may analyze the multiplex, as discussed above.

The initialization routine also determines the signal strength of the sampled signal received at the antenna element N at step 507. It should be appreciated that the signal strength information is useful in determining the individual antenna elements of hub 101 that are most desirable for communication between hub 101 and the node. Furthermore, as discussed above, the signal strength and/or distance information determined by the initialization procedure may be used to select a QAM rate to provide the greatest possible information density communication to a particular node. It should be appreciated that while such QAM selection is discussed herein with respect to initializing communication parameters, such determination may also be made dynamically at a later time in communication between the various nodes and the hub.

The initialization routine stores information determined in the above step at the data set associated with the particular node that responds to the control signal at step 508. It should be appreciated that such stored information may be used by hub 101 not only to initially allocate channels and individual antenna elements in communication with the node, but also to dynamically configure communications between devices in the event of a hardware failure or other event that causes a disruption in communications.

The initialization routine determines in step 509 whether all N antenna elements have been accessed by the above steps. Otherwise, the initialization process returns to step 502 to increment the antenna element counter N. If all antenna elements have been switched in, the initialization procedure with respect to the selection node stops.

Having stored attributes associated with each antenna element communication through hub 101 in the data set associated with the node, an initialization routine may perform statistical analysis on the data to determine communication parameters, such as the primary and secondary antenna elements with which communication may be conducted between the selected node and hub 101. It will be appreciated that information contained in a data set such as a high signal strength and a short propagation delay detected at an antenna element indicates the probability of a direct air link between the node and the hub 101. Similarly the initialization procedure may assign this antenna element for communication with the selected node. Since each antenna element is in TDM communication with the radio frequency modem, this allocation also identifies the timing of the communication window between the node and the hub 101.

As discussed above, the mapping of communication characteristics may be repeated for each node. The above statistical analysis may also compare the communication properties of other nodes when assigning antenna elements communicating with a selected node. For example, if it is determined that one antenna element provides the best communication between hub 101 and more than one node, only select channels available in the spectrum may be assigned to each such node. Alternatively, as discussed below with respect to the best mode for carrying out the invention, each such node may assign a different TDM burst within one channel upon which communication is effectuated. Alternatively, the initialization procedure may simply assign such an antenna element to one such node and assign an auxiliary antenna element to another such node that may provide less than optimal communication.

When determining the antenna elements and channels allocated to one of the nodes for communication with the hub 101, the initialization procedure transmits control signals to these nodes. The control signals may include information about the channels available for communication between a particular node as well as timing information to allow synchronization of communication between the node and the TDM antenna elements of the hub 101.

The timing information provided by the hub may include the above-mentioned offset determined during link initialization to allow a node to expect to transmit a burst cycle to the hub or delay receiving a burst cycle from the hub for a period of time sufficient to adjust the signal propagation delay. It should be appreciated that the inclusion of such offset information in the TDM timing information allows for the communication of information that is maximal over one burst period. Of course, the timing information may not include any offset information when maximum information communication is not required. Here, a delay period of sufficient duration to accommodate the propagation delay may be included in the burst period, in which no information is transmitted. However, it should be understood that such methods of compensating for signal propagation delays trade off for a reduction in throughput in order to accommodate the delay.

As previously discussed, the control information may be transmitted by the hub over a predetermined sub-channel for the control information or may be included in a logical channel or control channel embedded in the communication data packet, as discussed above. The node receiving such control information stores it in RAM470 for later use by central processing unit 460. Of course, using FDD by the hub 101, the RAM470 need not necessarily include timing information regarding the window in communication with the hub 101, and thus such information may be omitted from the control information. Likewise, communication between the hub and the nodes is only effected on a single channel, and information about the channels available for communication may be omitted from this control information.

As discussed above, this initialization information may also be used by the hub to dynamically allocate hub resources to nodes with which it communicates. It should be appreciated that by monitoring the communication of information between the node and the hub on a continuous basis, the hub can determine utilization statistics for any particular node. If it is determined that any one of such nodes is not sufficiently utilizing the hub resources available to that node, e.g., no information is transmitted on the channel assigned to that node, the hub may reassign such resources, or a portion of the resources, to another node. It should be understood that this reassignment may be accomplished by utilizing the control signals discussed in detail above.

Having described in detail various embodiments of the operation of the present invention, the best mode contemplated for practicing the present invention is now described. The above discussion has described Frequency Division Duplex (FDD) and Time Division Duplex (TDD) as means for allowing full duplex linking between the hub and a node or user. The best mode of practicing the invention contemplates using the TDD arrangement described below. This best mode will be described with respect to fig. 7 and 8.

Experiments have shown that providing TDD Tx and Rx frames with a single channel at each antenna element of hub 101, such as frames 351 and 352 shown in fig. 3B, allows for a desired reuse factor of the available channels. It should be understood that a cellular frequency reuse pattern of multiple hubs of the present invention is envisioned. Such a cellular diagram shows the added complexity of reuse of individual channels, since the use of channels of each hub must also take into account the use of channels of adjacent hubs.

Synchronization of transmission and reception at each antenna element is desirable in order to minimize the possibility of co-channel interference and to some extent reduce multipath interference. For example, each antenna element of hub 101 transmits only during a predetermined Tx frame and receives only during a predetermined Rx frame. Each hub of such a hub network may transmit and receive only at the same predetermined Tx and Rx frame synchronization. It should be appreciated that the above scheme defines a TDD communication system.

The available spectral division provides a convenient means by which to practice the present invention for each 10MHz discrete channel. Preferably, each antenna element of hub 101 is adapted to transmit and receive at least a single 10MHz channel, as defined by the system. As described above, antenna elements appropriate for a particular 10MHz channel may be distributed throughout hub 101 to provide reuse of each defined channel.

In addition, each Tx and Rx frame may be divided into discrete burst periods to provide TDMA utilization of each channel. Preferably, the Tx and Rx frames are divided into eight burst periods, 250 μ sec each, as shown in fig. 3B, so that full duplex can be synthesized in sixteen such burst periods. As previously described, the TDMA burst period may be further broken down into protocol slots; a protocol slot is a time sufficient for transmitting a packet formatted as a predetermined protocol. For example, each channel may be used to carry two 53 byte ATM cells in a TDMA burst period using QAM.

It should be appreciated that the use of 53 byte ATM cells is preferred because the protocol includes a 5 byte header that can be used by the present invention for routing information, as discussed in detail above. In addition, a sufficiently compressed data packet is provided using 53 byte ATM cells to provide a latency period when transmitting full duplex voice or other signals that are sensitive to delay or signal latency (latency).

A preferred embodiment of the formatting of information during a TDMA burst period is shown in fig. 3B as burst 360. Here each burst contains a ramp 361 followed by a preamble 362. The preamble 362 is followed by a CCH block 363. The CCH block 363 is followed by ATM cells 364 and 365, which are in turn followed by FEC block 366. FEC block 366 is similarly followed by ramp 367.

It should be appreciated that in the above identified TDMA burst cycle, ramps 361 and 367 are time periods within the burst cycle that allow the transmitter to reach full power and remove energy again without affecting the power at which message information is transmitted. Preamble 362 and Forward Error Correction (FEC) block 366, similar to the ramp component, are overhead components and are used to facilitate the transfer of information contained in ATM cells 364 and 365. In particular, the preamble 362 contains a dot pattern to resynchronize the symbol clock at the receiving station. FEC366 provides detection and correction of errors in transmitted information. As previously discussed, a Control Channel (CCH)363 is provided to convey system control information.

It should be understood that this example of information formatting is the only embodiment that utilizes TDMA burst-periodic communication. There are countless ways to communicate using the burst periods of the Tx and Rx frames disclosed above. For example, any of the components described above may be deleted, and many different components added, if desired. It should therefore be understood that the present invention is not limited to the format of the TDMA burst periods shown.

It should be appreciated that by utilizing QAM as previously discussed, the information density of each ATM cell of burst 360 may be increased. For example, using two ATM cells shown in fig. 3B with 4QAM, the realized slot capacity is 1/2DS 1. Furthermore, by utilizing increased modulation, this capacity can be increased. With 16QAM, the achieved slot capacity is 1DS 1; with 64QAM, the slot capacity achieved isDS 1; and with 256QAM, the slot capacity achieved is 2DS 1. It should be understood that any combination of these densities may be achieved by a single hub and/or antenna element using a variable rate modem and the initialization algorithm previously discussed.

It will be appreciated that the burst period of each Tx and Rx frame may be used by a single antenna element to provide channel TDMA to a plurality of nodes located within the radiation pattern of the antenna element. For example, burst periods 1 and 2 may be used by one antenna element to provide communication to a first node, while burst periods 3 through 7 are used by the same antenna element to provide communication to a second node. Likewise, a single Tx or Rx frame may be utilized by different antenna elements. For example, burst periods 1 through 4 may be used by a first antenna element to provide communication to a first node, while burst periods 5 through 8 are used by a second antenna element to provide communication to a second node.

It will be appreciated that the above-mentioned combination of TDMA's, the use of the burst period by a single antenna element and the separation of Tx and Rx frames between different antenna elements may be utilized by the present invention. For example, burst periods 1 and 2 may be used by one antenna element to provide TDMA communication to a first node and a second node, while burst periods 3 and 4 may be used by a second antenna element to provide communication to a third node.

While balanced duplexing is shown by the eight forward channel and eight reverse channel burst periods in fig. 3B, it should be understood that any combination of forward and reverse channel profiles may be utilized with the present invention. Of course, when all burst periods are used in either forward or reverse direction, time division duplexing can no longer be achieved by that channel.

Experiments have shown that information such as that conveyed by the system of the present invention generally falls into one of three categories; those are substantially balanced full duplex communications, primarily downlink communications, and primarily uplink communications. Thus, these communication needs may be satisfactorily met by one embodiment of the present invention utilizing any one of the three duplexing schemes of a particular user.

The first duplexing scheme is the 50% forward 50% reverse channel allocation for the burst period described above with reference to TDD. It will be appreciated that a 50%/50% allocation is advantageous, an important amount of information being both transmitted in the downlink as well as in the uplink.

The second duplex scheme is: approximately 94% of the burst period is used to transmit information from the hub to one node (downlink) and the remaining 6% of the burst period is used to transmit information in the reverse direction (uplink). Preferably such a 94%/6% duplexing scheme is implemented using fifteen burst periods of the sixteen burst periods shown in fig. 3B as downlink burst periods and the remaining one burst period as an uplink burst period.

A 94%/6% allocation is advantageous where an important amount of information is transmitted on the downlink, but little or no information is transferred on the uplink. It should be appreciated that 6% reverse channel communication is preferably maintained by the present invention even where the user does not require reverse channel information communication, since this small amount of bandwidth may be used by the system for link maintenance and control functions such as those previously described. This 6% reverse channel communication may be used, for example, to request retransmission of data packets, to request adjustment of the amplitude of the transmitted signal, TDM timing information, to dynamically allocate hub resources, or to monitor the communication properties for adjustment of the periodicity of QAM modulation.

The third duplex scheme is: approximately 6% of the burst period is used to transmit information from the hub to a node (downlink) and the remaining 94% of the burst period is used to transmit information in the reverse direction (uplink). It should be appreciated that this scheme is simply the opposite of the 94%/6% scheme discussed above, providing communication of a significant portion of the information in the uplink direction.

While it is possible to define a combined TDD frame rather than the three frame combination discussed above, and to define the Tx and Rx frame combination of each of the respective schemes to include a different number of individual burst periods, the preferred embodiment defines the scheme for a predetermined number of combinations, where each combination includes the same total number of burst periods. It should be appreciated that the three combinations of duplexing discussed above satisfactorily serve the generally skilled information communication requirements. Also, the number of links using the TDD scheme, where each scheme accomplishes forward and reverse channel communication for the same total number of frames of a burst period, is advantageous in reusing channels in the system. The reuse pattern of individual channels in both a single hub and a cellular frequency reuse pattern is simplified by the limited number and timing of such schemes.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (81)

1. A system for providing broadband information communication between a plurality of locations, said system comprising:

a plurality of nodes, each node having associated therewith at least one node adapted for broadband communication in a frequency band of the millimeter wave spectrum, the node antenna having a single predetermined communication beam providing directional communication, the plurality of nodes comprising:

a first node of the plurality of nodes adapted to communicate over at least a first band of the millimeter-wave spectrum; and

a second node of the plurality of nodes adapted to communicate over at least a second band of the millimeter-wave spectrum; and

a processor-based communications hub comprising:

a plurality of hub antennas, each hub antenna having a predetermined communication beam providing directional communication; wherein at least one hub antenna of the plurality of hub antennas is switchably connected to an internal signal provided within the hub;

a first hub antenna of the plurality of antennas adapted to communicate with the first node over the first frequency band of the millimeter-wave spectrum; and

a second hub antenna of the plurality of antennas adapted to communicate with the second node over the second frequency band of the millimeter-wave spectrum.

2. The system of claim 1, wherein the first and second frequencies are the same.

3. The system of claim 1, wherein the first and second hub antennas are the same.

4. The system of claim 1, wherein said hub is coupled to a communications backbone.

5. The system of claim 4, wherein broadband access is provided between said hub and said connected communication backbone.

6. The system of claim 4, wherein said communication backbone comprises an information communication link selected from the group consisting of:

a public switched network;

a cable communication network;

a broadband data stage connection; and

an internetwork.

7. The system of claim 1, wherein said hub is expandable to provide additional directional communication through coupling connected individual antenna units such that said connected individual antenna units become a hub antenna of said plurality of hub antennas.

8. The system of claim 1, wherein said hub further comprises a first radio frequency modem, said first modem providing said internal signal, switchably connected to said at least one hub antenna.

9. The system of claim 8, wherein said hub further comprises a second radio frequency modem, said second modem providing a second internal signal switchably connected to said at least one hub antenna.

10. The system of claim 8, wherein said first modem is dynamically configured to provide a variable information density within said internal signal.

11. The system of claim 10, wherein communications between one of the plurality of hub antennas and one of the plurality of nodes are sampled to identify at least one communication parameter.

12. The system of claim 11, wherein the variable information density is dynamically configured in accordance with the at least one communication parameter.

13. The system of claim 12, wherein the at least one communication parameter is selected from the group consisting of:

an error rate of the received signal;

signal to noise ratio;

a signal-to-interference ratio;

a power level of the received signal;

a distance between the one of the plurality of hub antennas and the one of the plurality of nodes; and

a signal propagation delay experienced by a communication between the hub and one of the plurality of nodes.

14. The system of claim 1, wherein said internal signal is time-divided and includes a plurality of information bursts.

15. The system of claim 14, wherein said plurality of information bursts comprises at least one information burst of a forward channel group and one information burst of a reverse channel group.

16. The system of claim 15, wherein the bursts for the forward channel group and the bursts for the reverse channel group each comprise a predetermined number of bursts that are reused according to a frequency at the hub.

17. The system of claim 16, wherein the predetermined number of bursts is dynamically configurable.

18. The system of claim 15, wherein the bursts of the forward channel group comprise a different number of bursts than the bursts of the reverse channel group.

19. The system of claim 15, wherein said forward channel information includes a predetermined percentage of said plurality of information bursts and said reverse channel information bursts include a remaining percentage of said plurality of information bursts.

20. The system of claim 19, wherein said forward and reverse channel information bursts comprise a percentage of said plurality of information bursts selected from the group consisting of:

about 94% forward channel information bursts and about 6% reverse channel information bursts;

about 50% forward channel information bursts and about 50% reverse channel information bursts; and

about 6% forward channel information bursts and about 94% reverse channel information bursts.

21. The system of claim 1, wherein said switchable connection is implemented according to a predetermined manner to provide time division multiple access of said internal signal to one of said plurality of hub antennas.

22. The system of claim 21, further comprising:

means for the hub to initially communicate with one of the plurality of nodes according to a predetermined pattern; and

means for causing attributes of initial communications with one of the plurality of nodes to be stored at the hub.

23. The system of claim 22, wherein the predetermined manner is determined at least in part based on the stored attributes.

24. The system of claim 1, wherein one of said plurality of nodes further comprises a radio frequency modem, said modem connected to said node antenna.

25. The system of claim 24, wherein said modem is dynamically configurable, providing variable information density.

26. The system of claim 25, wherein said modem is adapted to provide a particular information density when a control signal is received from said hub.

27. The system of claim 25, wherein said variable information density comprises using quadrature amplitude modulation.

28. The system of claim 24, wherein the signal from the modem is time divided and includes a plurality of information bursts.

29. The system of claim 28, wherein said plurality of information bursts comprises a forward channel information burst and a reverse channel information burst.

30. The system of claim 29, wherein said forward channel information burst comprises a predetermined percentage of said plurality of information bursts and said reverse channel information burst comprises a remaining percentage of said plurality of information bursts.

31. The system of claim 30, wherein defining said forward and reverse channel information bursts comprises a percentage of said plurality of information bursts selected from the group consisting of:

about 94% forward channel information bursts and about 6% reverse channel information bursts;

about 50% forward channel information bursts and about 50% reverse channel information bursts; and

about 6% forward channel information bursts and about 94% reverse channel information bursts.

32. The system of claim 30, wherein the predetermined percentage is dynamically adjustable.

33. The system of claim 1, wherein the first and second frequency bands are in the range of 10 to 60 GHz.

34. The system of claim 1, wherein one of the plurality of hub antennas comprises a mixed mode lens corrected horn (hybrid mode lens corrected horn) providing a gain of about 32dB with a predetermined communication lobe of about 16 degrees, operating in the range of 10 to 60 GHz.

35. The system of claim 1, wherein one of the plurality of nodes comprises an antenna comprising a dish antenna providing approximately 42dB of gain, having a predetermined communication lobe of approximately 2 degrees, operating within 10 to 60 GHz.

36. The system of claim 1, further comprising a plurality of processor-based communication hubs, said plurality of hubs positioned to provide a cellular communication frequency reuse map.

37. The system of claim 36, wherein one of said plurality of hubs communicates information over a link provided at least in part by an antenna unit of each of said plurality of hubs.

38. The system of claim 37, wherein the link provides broadband access between hubs of the plurality of hubs.

39. The system of claim 37, wherein said information communication link is used, at least in part, to provide an information backhaul between at least two hubs of said plurality of hubs.

40. The system of claim 36, wherein one of said plurality of hubs communicates information over a link provided by a physical link interconnecting each of said plurality of hubs.

41. The system of claim 1, further comprising a first set of hub antennas of said plurality of antennas adapted to communicate over at least said first frequency band of said plurality of frequency bands, each hub antenna of said first set being arranged to provide substantially non-overlapping directional communications.

42. A communications hub for providing communication of information between locations dispersed over a plurality of addresses, the communications hub comprising:

a first radio frequency modem providing a first signal;

a plurality of hub antenna units, each hub antenna unit having a predetermined radiation pattern providing directional communications, one of the hub antenna units providing communications to a different one of the geographically separated locations, the plurality of hub antenna units including a first group having at least one hub antenna unit associated therewith; and

switching means for switchably connecting said first set to said first signal, said switching means providing said first set of time division multiple access to said first signal.

43. The communications hub of claim 42, further comprising:

a second group having at least one hub antenna associated therewith, wherein the first and second groups are not mutually exclusive; and

a second radio frequency modem providing a second signal, and said converting means further comprises means for switchably connecting said second set to said second signal, said converting means providing said second set of time division multiple access to said second signal.

44. The communications hub of claim 42, wherein a first set of hub antennas of the plurality of antenna units is adapted to communicate over a first band of the millimeter wave spectrum and a second set of hub antennas of the plurality of antenna units is adapted to communicate over a second band of the millimeter wave spectrum.

45. The hub according to claim 42, wherein said hub is adapted to receive a coupling of individual antenna units such that said connected individual antenna unit becomes a hub antenna of said plurality of hub antenna units.

46. The hub according to claim 45, wherein said connected individual antenna elements are positioned to provide directional communication to an area not previously within a composite antenna element radiation pattern provided by said communication hub.

47. The hub of claim 45, wherein placement of said connected individual antenna units provides directional communication to an area not previously within a composite antenna unit radiation pattern provided by said communication hub, said connected individual antenna units adapted to provide increased communication capacity in said area.

48. The hub of claim 42, wherein said first signal is time-divided and includes a plurality of information bursts.

49. The hub of claim 48 wherein said plurality of information bursts comprises a set of forward channel information bursts and a set of reverse channel information bursts, said forward and reverse channel information bursts each being defined to comprise a percentage of said plurality of information bursts that together represent 100%.

50. The hub according to claim 49, wherein said forward channel and said reverse channel percentages are selected from the group consisting of:

about 94% forward channel information bursts and about 6% reverse channel information bursts;

about 50% forward channel information bursts and about 50% reverse channel information bursts; and

about 6% forward channel information bursts and about 94% reverse channel information bursts.

51. The hub according to claim 42, wherein said switchable connection is implemented according to a predetermined manner to provide time division multiple access of said first signal to antenna elements of said first group.

52. The hub of claim 51, wherein said predetermined pattern is determined at least in part by said communication attribute provided by one of said plurality of antenna elements.

53. The hub according to claim 42, wherein said first modem is dynamically configured to provide a variable density of information within said first signal.

54. The hub of claim 53, wherein said variable information density comprises a quadrature amplitude modulation of an input signal.

55. The hub of claim 53, wherein said variable information density is dynamically configurable based, at least in part, on a property of said communication provided by one of said plurality of antenna elements.

56. The hub of claim 55, wherein said attribute of said communication is selected from the group consisting of:

an error rate of the received signal;

a signal-to-noise ratio of the communication;

a signal-to-interference ratio of the communication;

a power level of the received signal;

a distance of the communication; and

the signal of the communication propagates.

57. The hub according to claim 42, wherein the hub is positioned to provide communication in a predetermined cell comprising a cellular overlay of a plurality of communication hubs.

58. The hub according to claim 57, wherein the hub is connected to at least one of the plurality of hubs via a communications backbone.

59. The hub according to claim 58, wherein said communication backbone is selected from the group consisting of:

a public switched network;

a cable communication network;

a broadband data stage connection; and

an internetwork.

60. The hub according to claim 57, wherein the hub is in information communication with at least one of the plurality of hubs via an air link provided at least in part by an antenna unit of the plurality of antenna units.

61. The hub of claim 42, wherein the band of millimeter wave spectrum is in the range of 10 to 60 GHz.

62. The hub of claim 42, wherein one of the plurality of hub antennas comprises a hybrid mode lens corrected horn (hybrid lens corrected horn) operating in the range of 10 to 60GHz providing approximately 32 to 38dB gain with a predetermined communication lobe of approximately 4 to 20 degrees.

63. A system for providing broadband information communication between a plurality of processor-based systems, the system comprising:

a first communications node connected to a first processor-based system, the first node comprising:

a communication unit comprising an antenna, a first radio frequency modem and a first communication module connected therebetween, said antenna being adapted to receive radio frequency communications in the extremely high frequency spectrum; and

a first controller unit comprising a processor connected to a first electronic memory and to an interface, said processor also being connected to said first modem, said interface being adapted to be connected to a processor-based system;

a second communication node connected to a second processor-based system, the second node comprising:

a communication unit comprising an antenna, a second radio frequency modem and a second communication module connected therebetween, said antenna being adapted to receive radio frequency communications in the extremely high frequency spectrum; and

a second controller unit comprising a processor connected to a second electronic memory and to an interface, said processor also being connected to said second modem, said interface being adapted to be connected to a processor-based system;

a communications hub adapted for information communication with the first node and the second node, wherein the hub comprises a plurality of radio frequency modems, wherein each modem is switchably connected to at least one module of the plurality of antenna elements by a switch, the hub comprising:

a plurality of antenna elements, each antenna element of said plurality of antenna elements adapted to receive radio frequency communications in the extremely high frequency spectrum, each antenna element of said plurality of antenna elements having a hub communication module connected thereto;

a third radio frequency modem switchably connected to at least one module of the plurality of antenna elements by a first switch, the third modem adapted to receive the communications from the hub module;

a third controller unit comprising a processor connected to a third electronic memory and to said first and second switches, said processor also being connected to said third modem;

wherein the first, second and third radio frequency modems are adapted to transmit information having different predetermined information densities, and each of the first, second and third modems is dynamically configurable to select one of the different predetermined information densities.

64. The system of claim 63, wherein the hub is adapted to receive individual antenna elements to its connection so that the connected individual antenna element becomes one of the plurality of antenna elements.

65. The system of claim 63, wherein one of the antenna elements comprises a group of antenna elements, the antenna elements comprising the group having substantially non-overlapping radiation patterns.

66. The system of claim 63, wherein one of the antenna elements comprises a first group of antenna elements and the other of the antenna elements comprises a second group of antenna elements, and wherein the one of the antenna elements of the first group has a radiation pattern that substantially overlaps the one of the antenna elements of the second group.

67. The system of claim 63, wherein the hub includes a plurality of radio frequency modems, each modem of the plurality of modems switchably connected to at least one module of the plurality of antenna elements by a switch.

68. The system of claim 63, wherein each of said first, second and third modems is adapted to transfer information at various predetermined information densities.

69. The system of claim 68, wherein each of said first, second and third modems is dynamically configured to select one of said various predetermined information densities.

70. The system of claim 63, wherein said hub is further adapted to be coupled to an information communication backbone.

71. The system of claim 70, wherein said communication backbone provides for communication of information between a plurality of hubs, each hub of said plurality of hubs positioned to provide for communication of information within a substantially non-overlapping predetermined area.

72. The system of claim 63, wherein said third controller unit transmits information communications received by said hub for transmission by said hub in accordance with information contained within said information communications.

73. A system according to claim 63, wherein said third controller unit transmits information communications received by said hub for transmission by said hub in accordance with information stored within said third controller unit.

74. The system of claim 63, wherein the very high frequency spectrum is a band of about 1.4GHz at about 38 GHz.

75. A system according to claim 63, wherein said hub communications module is adapted to convert said received very high frequency to a first intermediate frequency, and said first communications module is further adapted to convert said first intermediate frequency to a second intermediate frequency.

76. The system of claim 75, wherein said first intermediate frequency is about 3 GHz.

77. The system of claim 75, wherein said second intermediate frequency is approximately 400 to 500 MHz.

78. The system of claim 63, wherein said antenna comprises a dish antenna providing about 42dB gain with a predetermined communication lobe of about 2 degrees.

79. The system of claim 63, wherein one of the plurality of antenna elements comprises a mixed mode lens correction horn providing approximately 32dB gain with a predetermined communication lobe of approximately 16 degrees.

80. The system of claim 63, wherein said first switch is controlled by said processor according to a pattern stored in said second electronic memory.

81. The system as recited in claim 80 wherein said hub further comprises an initialization algorithm stored in said third electronic memory, said initialization algorithm causing said hub to communicate with one of said first and second nodes, said initialization algorithm further causing attributes of said communication with one of said first and second nodes to be stored in said third memory.

82. The system of claim 81, wherein said first controller unit of said first node controls the communication of information between said first node and said hub based, at least in part, on said manner and said communication attributes stored in said second electronic memory.