HK1030325B - A method of and apparatus for paging a wireless terminal in a wireless telecommunications system - Google Patents

Description

Method and apparatus for paging a wireless terminal in a wireless telecommunications system

Technical Field

The present invention relates to a method and apparatus for paging a wireless terminal in a wireless telecommunications system. More particularly, the present invention relates to a novel and improved method for paging a cellular telephone or other wireless communication device. Paging may be affected using the quick paging channel and the full paging channel.

Description of the Related Art

The IS-95 cellular telephone standard (and its derivatives such as IS-95A and ANSI J-STD-008, which are collectively referred to herein as IS-95) uses advanced signal processing techniques to provide efficient, high quality cellular telephone service. For example, IS-95 compliant cellular telephone systems utilize speech signal encoding, error detection, Forward Error Correction (FEC) interleaving, and spread spectrum modulation to more efficiently utilize the available RF bandwidth and provide a more robust connection. In general, the benefits provided by IS-95 include longer talk time, higher capacity, and fewer dropped calls when compared to other types of cellular telephone systems.

To direct communications in sequence, IS-95 provides a set of highly encoded signals on which to transmit data having different functions. These highly coded channels include paging channels over which paging messages are sent that inform cellular telephones or other types of wireless terminals of incoming requests for communication. According to the IS-95 standard, paging messages are sent at low to medium rates (4800 or 9600bps) during time slots pre-allocated to a cellular telephone group. Table I provides data contained in a general paging message as a typical example of a paging message generated basically according to the IS-95A standard.

Message field	Length (bit)
		MSG _ TYPE (message TYPE)	8
CONFIG_MSG_SEQ	6
		ACC_MSG_SEQ	6
CLASS_0_DONE	1
		CLASS_1_DONE	1
RESERVED	2

BROADCAST_DONE	1
		RESERVED	4
ADD_LENGTH	3
		ADD_PFIELD	8×ADD_LENGTH

And zero or more of the following page records occur:

PAGE_CLASS	2
		PAGE_SUBCLASS	2
paging class specific field	Typically 2-12 bits

Table I.

Table I is provided only to show the length of a typical paging message, so the function of each field is not described in detail herein. However, these detailed descriptions can be obtained by reference to the known publicly available IS-95 standard (particularly the IS-95A standard). The paging message also begins with an eight-bit message length field (MSG _ LEN), which indicates the length of the message, and ends with a 30-bit Cyclic Redundancy Check (CRC) field (not shown).

To monitor for paging messages, the cellular telephone periodically monitors the paging channel during the assigned paging slot. In particular, cellular telephones periodically activate complex RF and digital signal processing circuitry as long as is necessary to successfully process signal messages. Since typical paging messages are relatively long and are transmitted over highly encoded low to medium rate channels, the associated processing during each paging slot requires a significant amount of time and paging processing resources, and thus a significant amount of power, to complete. This reduces the time that an IS-95 cellular telephone can remain in standby mode using a battery of a given capacity and IS therefore less desirable.

Summary of The Invention

In one aspect, the present invention provides a method for paging a wireless terminal in a wireless telecommunications system, comprising: transmitting a quick paging message through a lower degree code channel; and generating the full page message over a more highly coded channel.

In another aspect, the present invention provides a method for paging a wireless terminal from a group of wireless terminals, comprising: a) sending a quick page message directed to the subset of wireless terminals that includes the wireless terminal; and b) generating a full page message identifying the wireless terminal.

The present invention also provides a method for paging a wireless terminal, comprising: a) generating a full paging message; and b) generating a full page message, wherein the quick page message contains substantially less data than the full page message.

The present invention still further includes a method of receiving a paging message, comprising the steps of: a) monitoring a quick paging channel for quick paging messages; and b) monitoring the full paging channel when a quick page message is received.

The present invention also provides an apparatus for paging a wireless terminal in a wireless telecommunication system, the apparatus comprising: means for transmitting a quick page message over a lower degree code channel; and means for generating a full page message over the higher degree encoded channel.

The present invention is embodied in a novel and improved method and system for paging a cellular telephone or other wireless terminal that reduces standby mode power consumption. Two paging channels may be employed. According to one embodiment of the present invention, a minimum code quick paging channel is established over which quick paging messages are transmitted in one of a group of quick paging slots. The quick page message indicates that a communication request has been received and that the receiving communication terminal should process the highly encoded full page channel transmitted during the next full page slot for the more detailed full page message. The communication terminal monitors the full paging channel after receiving the quick page message on the quick paging channel.

To page a communication terminal, the base station controller first generates a quick page message during a quick page slot assigned to a group of communication terminals including the particular communication terminal being paged. Thereafter, the full page message identifies the particular communication terminal. The communication terminal periodically monitors the quick paging slot and, upon detecting a quick page, activates decoding circuitry to process the full paging channel. Once the full paging channel is processed, the communication terminal determines whether to send a full paging message directly to it, and if not, deactivates the decoding circuit and returns to processing the quick paging channel.

Drawings

The foregoing and other features, objects, and advantages of the invention are apparent from the following detailed description of embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views:

FIG. 1 is a block diagram of a cellular telephone system;

FIG. 2 is a timing diagram showing time slots in the quick paging channel and the full paging channel;

FIG. 3 is a flowchart showing steps performed during paging of a wireless terminal;

FIG. 4 is a block diagram illustrating encoding performed on the full paging channel and the quick paging channel;

FIG. 5 is a flowchart showing steps performed by a wireless terminal during standby mode; and

fig. 6 is a block diagram of a receiver constructed in accordance with an embodiment of the invention.

Detailed description of the preferred embodiments

Methods and systems for reducing standby mode power consumption for paging a cellular telephone or other wireless terminal are described. Two paging channels may be employed. In the following description, embodiments of the present invention are described with respect to a cellular telephone system operating substantially in accordance with the IS-95 standard. Although the present invention is particularly well suited for operation in such an environment, a number of other digital communication systems may benefit from the use of the present invention, including TDMA-based wireless communication systems, satellite-based communication systems, and wireless systems over which encoded signaling is transmitted.

Fig. 1 is a block diagram of a highly simplified cellular telephone system constructed for use with the present invention. Wireless terminals 10 (typically cellular telephones) are located between base stations 12. Wireless terminals 10a and 10b are in active mode and are connected to one or more base stations 12 by modulating radio frequency signals in accordance with the CDMA signal processing techniques of the IS-95 standard. Systems and methods for processing RF signals substantially in accordance with the use of the IS-95 standard are described in U.S. patent No. 5,103,459 entitled "system and method for generating signal waveforms in a CDMA cellular telephone system," assigned to the assignee of the present invention and incorporated herein by reference (the' 459 patent). The other wireless terminals 10 are in standby mode and therefore monitor for signal messages indicative of a communication request.

In the preferred embodiment of the present invention, each base station generates a forward link signal that includes a set of forward link channels. Channels are established by a set of orthogonal 64 chip (or bit) Walsh codes, each of which is used to modulate data associated with a particular channel. The channels are classified according to function and include a pilot channel on which a phase offset pattern is repeatedly transmitted, a synchronization channel on which synchronization data including absolute system time and a phase offset of the associated pilot channel is transmitted, and a traffic channel on which data directed to the terminal is transmitted. A traffic channel is typically allocated to transmit data to a particular wireless terminal 10 for the duration of the connection with that particular base station.

Further, in accordance with an embodiment of the present invention, one or more of the Walsh channels are designated as quick paging channels and one or more of the Walsh channels are designated as full paging channels. The assignment and operation of the full paging channel IS preferably performed according to the paging channel specified by the IS-95 standard. Some methods and apparatus for performing paging substantially in accordance with the IS-95 standard are described in U.S. patent No. 5,392,287 (the '287 patent) entitled "apparatus and method for reducing power consumption in a mobile communication receiver") and patent No. 5,509,015 (the' 015 patent) entitled "method and apparatus for scheduling communications between transceivers," both of which are assigned to the assignee of the present invention and incorporated herein by reference.

As described in the '287 and' 015 patents, and as specified by the IS-95 standard, the full paging channel time IS divided into time "slots". The time slots are then assigned to groups of wireless terminals, where the assignment is performed based on an international mobile subscriber id (imsi) or other terminal identification information such as one or more Mobile Identification Numbers (MINs) that is unique for each wireless terminal 10. In other embodiments of the present invention, other identification information is also utilized, including the Electronic Serial Number (ESN) or temporary mobile subscriber id (tmsi) of the wireless terminal. Others can identify additional values that can be employed. The various possible identification information that may be employed will be referred to collectively below as the MOBILE ID. The quick paging channel is also divided into time slots.

Fig. 2 is a timing diagram illustrating the time slots of a full paging channel and a quick paging channel when constructed in accordance with one embodiment of the present invention. The quick paging channel is divided into quick paging slots 30 and the full paging channel is divided into full paging slots 32, the latter preferably being longer in duration than the quick paging slots. Groups or clusters of quick paging slots are assigned to a single full paging slot 32, shown by the diagonal arrows, although a one-to-one correspondence or other ratio between quick paging slots and full paging slots is utilized consistent with the use of the present invention. The quick paging slot 30 is preferably assigned to a particular group of wireless terminals by using a hashing function for the MOBILE ID of the wireless terminal 10.

To page a particular wireless terminal 10, a quick page message is transmitted during the quick page slot and a full page message is transmitted during the full page slot assigned to that wireless terminal. The quick paging slot and the full paging slot occur in a periodically repeating manner that ensures that a slot associated with a particular terminal occurs after a limited time. As shown in fig. 2, a full page slot 32 is delayed 34 after the associated quick page slot 30 to allow the wireless terminal to process the quick page message and to activate additional decoding circuitry before the next full page slot.

Fig. 3 is a block diagram of the steps performed by the BSC14 during the paging process. The paging process begins at step 36 and a determination is made in step 38 whether a communication request is received. If not, step 38 is performed again.

If a communication request is received, then in step 40, the full paging slot and the quick paging slot associated with the wireless terminal to which the communication request directly arrived are calculated based on the MOBILE ID or other identifying information of the wireless terminal 10. In one embodiment of the invention, a quick paging slot is calculated using a first hash function, and a full paging slot is calculated using a second hash function, wherein the second hash function is different from the first hash function. Further, the full paging slot is approximately 80 milliseconds, and the quick paging slot is approximately 5 milliseconds. The wireless terminal 10 must process all or part of the full paging channel depending on the content of the paging message received pursuant to IS-95. The BSC14 preferably executes software using one or more microprocessors stored in memory (not shown) to perform the required processing.

In an exemplary embodiment of the present invention, the full paging slot is determined according to the above-mentioned '287 and' 015 patents, and the quick paging slot is determined by applying another hash function to the MOBILE ID, although other methods of assigning paging slots to wireless terminals are consistent with the use of the present invention. In particular, the full paging slot corresponds to the system time t, assuming in a 20 ms frame that the following equation holds:

(floor(t/4)-PGSLOT)mod(16*T)＝0 (1)

where T is 1.28 seconds (from T2)ⁱGiven) slot cycle length in units, where I is the Slot Cycle Index (SCI). PGSLOT is determined using the following hash function:

PGSLOT＝floor(N×((40505×(LHDECORR))mod2＾16)/2＾16)(2)

where L is the 16 least significant bits of the 32-bit HASH KEY, and H is the 16 most significant bits of HASH KEY, and N is 2048. The HASH KEY is preferably the MOBILE ID or some derivative thereof and the IMSI. The function floor (x) returns the largest integer less than or equal to x. For example, the results for floor (2.99), floor (2.01) and floor (2.00) are 2, while the result for floor (-2.5) is-3. The decorrelation (decorrelation) value DECORR is calculated as follows:

DECORR＝6×HASH_KEY[0...11] (3)

where HASH _ KEY [0.. 11] is the 11 least significant bits of the 32-bit HASH KEY value.

In a similar manner to the full paging slot, a hash function is calculated for determining the quick paging slot in the preferred embodiment of the present invention, except that the quick paging slot occurs between 40 and 120 milliseconds before the full paging slot, and the group of wireless terminals assigned to a quick paging slot varies over time to ensure that each wireless terminal 10 is associated with a different group of wireless terminals 10 during each quick paging slot. Changing the set of terminals 10 associated with each wireless terminal 10 during each paging slot helps to ensure that less active wireless terminals are not permanently associated with more active wireless terminals 10 and thus do not have to monitor a large number of full paging messages that are not sent directly to it.

In one exemplary embodiment of the present invention, the quick paging slot for the wireless terminal 10 occurs within an 80 ms quick paging cycle that begins 120 ms before the beginning of the full paging slot, as calculated by the following equation:

(floor((t-6)/4)-PGSLOT)mod(16*T)＝0 (4)

where PGSLOT is the same as for the full paging slot. The duration of the quick paging cycle is preferably 80 milliseconds. The quick paging cycle is divided into quick paging slots during which quick paging messages occur, as will be described in more detail below. Preferably, the quick paging slot and associated quick paging message are a single bit in duration. Thus, the number of quick paging slots per quick paging cycle is a function of the data rate of the quick paging channel.

It is apparent that equation (4) is the same as equation (1), except that the system time is offset by 6 frames, which results in the quick paging cycle starting 120 milliseconds before the full paging slot. The offset of 120 milliseconds ensures that there is at least 40 milliseconds (assuming an 80 millisecond quick page cycle) between any particular quick page slot and the full page slot, which gives the wireless terminal sufficient time to prepare a full page message after receiving a quick page message.

During an 80 ms quick paging cycle, the quick paging slot (having a duration of 1 bit) assigned to a particular wireless terminal 10 is determined using the following equation:

QUICK_PGSLOT＝1+floor(N×((40505×(LHDECORR))mod 2^16)/2^16)(5)

while setting the value N to the quick paging channel time rate (QPAGE RATE) is the number of bits per 80 millisecond slot. For example, if the quick paging channel time is 9600 bits/second, then the value QPAGE _ RATE equals 768 bits/frame. Further, the decorrelation value is set as follows:

DECORR＝floor((t-6)/64)mod2^16 (6)

equation (5) then returns a value between 1 and 768, which corresponds to a quick paging slot (or bit position) in an 80 ms quick paging cycle 120 ms before the corresponding full paging slot. The wireless terminal monitors the quick paging channel during its quick paging slot and if a quick paging message is received, the wireless terminal will monitor the full paging channel for a full paging message.

It is apparent from equation (6) that the decorrelation value DECORR of the QUICK paging channel is calculated as a function of system time, so that for a given set of wireless terminals 10, the resulting value QUICK _ PGSLOT will vary over time. This results in the group of wireless terminals 10 associated with a particular full paging slot having different quick paging slots over time (although they may still be paged within the same quick paging cycle), which helps to ensure that no instances occur where a less active wireless terminal 10 is tied to more active wireless terminals 10 that may result in monitoring the full paging channel at an unnecessary frequency, and therefore no unnecessary energy consumption.

If the MOBILE ID is not directly included in the communication request, the database may be queried by using any other identifying information included in the request, such as the telephone number or MOBILE Identification Number (MIN) of the wireless terminal 10.

Once the quick paging slot and the full paging slot are determined, the BSC14 sends the quick page message through one or more base stations 12 on the quick paging channel (in step 42), and the full page message on the full paging channel. The base station 12 encodes and modulates the paging channel as described in detail below, and the transmission of the two paging messages occurs during the respective quick paging slot and full paging slot.

After sending the quick page message and the full page message, the BSC14 polls for a response indicating that a page was received in step 46. If a response is received, the communication is started in step 50.

If no response is received after a period of time, a second quick page message is sent in step 52 and a second full page message is sent in step 54. The BSC14 polls for a response from the wireless terminal 10 in step 56 and determines whether the response was received in step 58. If the response is received, the communication is started in step 50. If it is determined in step 58 that no response has been received, the page fails in step 60. In another embodiment of the present invention, two or more quick page messages and two or more response full page messages are generated for each page. The second quick page message and the full page message increase the likelihood of receiving a page without introducing the delay required to determine whether an acknowledgement message has been received from the wireless terminal 10.

In the above preferred embodiment of the present invention, the quick PAGE message includes an INCOMMING _ PAGE bit. The INCOMMING-PAGE bit in a first state (e.g., logic high) indicates that a communication request has been received for one of the wireless terminals 10 associated with the quick paging slot, so that those wireless terminals process the full paging channel during the next designated full paging slot. An INCOMMING-PAGE bit in a second state (such as logic low) indicates that no communication request has been received for those wireless terminals 10 and therefore the full paging channel should not be processed during the next allocated full paging slot. Thus, the quick page message is encoded to a higher degree than the full page message, and can be processed with less resources because the page is represented by a single bit, rather than a substantially higher number of bits. These "message" encodings should not be confused with the "channel" encodings described below, where a higher number of encodings requires more data processing resources and is therefore less than ideal for power consumption.

In the preferred embodiment of the present invention, the full page message contains information specific to the normal page message in the IS-95 standard that allows each wireless terminal 10 to determine whether to send a page to it. An example of a page generated in accordance with the IS-95A standard IS provided in table I listed above. As shown in Table I, the full page message contains substantially more information than the quick page message, which preferably contains a single bit. Thus, the quick page message may be more easily processed by each wireless terminal 10 at less power than the full page message.

In another embodiment of the present invention, a multi-bit quick page message is employed. These multi-bit quick page messages are used to encode and convey additional information that not only simply indicates that the wireless terminal 10 should monitor the full paging channel during the next allocated full paging slot 32. For example, a multi-bit quick page message is applied to more specifically indicate which wireless terminals 10 are paged among the subset of wireless terminals that are reassigned to the corresponding quick page slot 30. The multi-bit quick page message may also be used to indicate that the full paging channel is monitored for a longer duration so that system parameter changes may be broadcast to all wireless terminals 10. Those skilled in the art will recognize a variety of useful information that may be transmitted using a multi-bit quick page message. Further, in another embodiment of the present invention, reduced forward error correction encoding is performed on the quick paging message.

In addition to sending less information in the quick page message, rather than the full page message, the preferred embodiment of the present invention incorporates a minimum coding scheme for the quick paging channel as compared to the full paging channel. Fig. 4 provides a coding scheme for the full paging channel and the quick paging channel according to one embodiment of the present invention.

As shown in fig. 4, data transmitted through the full paging channel is convolutionally encoded by a convolutional encoder 60, and the resulting encoded symbols are repeated by a symbol repeater 61 to generate symbols at a predetermined rate. Thus, the longer block repetition code symbols are blocked by the block interleaver 62. The data from the block interleaver is scrambled by EXCLUSIVE-OR (XOR) using the decimated long codes generated by long code generator 64 and decimator 66. The long code is a binary code generated in a predetermined manner as a function of the seed number and is known to all wireless terminals 10. The scrambled data IS modulated with a Walsh channel code designated for the full paging channel and transmitted using a pseudo-random noise code (PN code) PQSK spread the Walsh channel code modulated data, summed with data from other channels, and upconverted, preferably in accordance with the IS-95 standard (spreading, summing, and upconverting, not shown).

Still referring to fig. 4, the data transmitted over the quick paging channel is directly used to the Walsh channel code assigned to the quick paging channel, and then spread, summed, and upconverted as described above. Preferably, a single data bit transmitted over the fast channel is modulated multiple times with the same Walsh code, effectively transmitting the bit multiple times. One may also repeat the transmission of data bits using a symbol repeater (like symbol repeater 61) for the full paging channel. In yet another embodiment of the present invention, the quick paging channel is scrambled using a long code, as is performed for the full paging channel.

As is apparent from fig. 4, the processing associated with transmitting the channel on the quick paging channel is substantially less in duration and complexity than that associated with the full paging channel. Thus, the amount of processing required to perform the receive processing of the quick paging channel is substantially small, thus requiring less energy than that required for the full paging channel. While reducing the amount of processing performed on the quick paging channel increases the likelihood of error during the processing of any particular bit, other methods may be employed that have the effect of reducing this increased error rate without substantially increasing complexity. The method includes transmitting the same bit multiple times or interpreting a low quality transmission as a paging message as described below.

Fig. 5 is a block diagram of a process performed by the wireless terminal 10 in standby mode when performed according to one embodiment of the present invention. The processing is preferably performed using a microprocessor controller via software instructions stored in a memory coupled to other integrated circuits and systems known in the art (not shown). The process begins in steps 80 and 84, which determines that the assigned quick paging slot has arrived, and if not, step 82 is performed again.

If the assigned quick paging slot arrives, the wireless terminal 10 processes the quick paging channel in step 86. Preferably, the processing is performed using a much smaller subset of the signal processing circuitry included in the wireless terminal than is used to process the full page message. The receive processing preferably includes down-converting the received RF energy, despreading with a PN spreading code, and demodulation with an assigned Walsh code, based on the transmit processing performed for the quick paging channel as shown in fig. 4. The resulting soft determination is processed directly to determine the logic level of the transmission.

Referring again to fig. 5, in step 88, it is determined whether a quick page message is received in step 86 based on the logic level of the detected data. If a quick page message is detected, processing continues in step 90 as described above. If no quick page message is detected, then a further determination is made in step 89 as to whether to accept the signal quality during processing of the quick paging channel. If so, the wireless terminal 10 returns to step 82. If signal quality is not received, processing continues in step 90 as described below.

The received signal quality may be determined by various known methods including determining when the received power of the signal transmitted by the retransmission engine 50 is below a threshold, or by determining when the signal-to-noise ratio of the pilot channel is below a predetermined threshold. By monitoring for full page messages when the received paging quality is unacceptable, the number of missed full page messages due to undetected quick page messages due to unacceptable paging quality is minimized.

If a quick page message is detected or the received paging quality is unacceptable, the wireless terminal 10 activates the additional decoding circuitry in step 90 and processes the full paging channel using the activation circuitry during the full paging slot in step 92. The time between the quick paging slot and the full paging slot assigned to a particular terminal must be sufficient to allow the additional decoding circuitry to be activated within the wireless terminal 10 after the quick paging message is detected before the full paging slot occurs.

In step 94, the wireless terminal 10 determines whether the full page message processed in step 92 was directed to it based on the address contained in the message, and if not, then in step 82 the decoding circuitry within the wireless terminal 10 is deactivated and step 84 is performed again. If the full page message is to be sent directly to the wireless terminal 10, then processing for the corresponding communication begins in the wireless terminal in step 96 and the wireless terminal enters the active mode in step 98.

Fig. 7 is a block diagram providing a highly simplified representation of a wireless terminal 10 when constructed in accordance with an embodiment of the present invention. Digital demodulator 302, block interleaver 304, trellis decoder 306, and control system 308 are coupled via a digital bus, and RF receiver 300 is coupled to digital demodulator 302.

During standby mode, the control system intermittently activates RF receiver 300 and digital demodulator 302 to process the pilot and quick paging channels. RF receiver 300 downconverts and digitizes RF paging and digital demodulator 302 performs digital demodulation for the duration to produce soft decision data for the channel being processed. The control system 308 tests the pilot channel soft decision data to determine the quality of the page and detects the quick paging channel to determine if a quick page message has been received.

If a quick page message has been received, or a page with poor quality has been received, control system 308 activates block deinterleaver 304 and trellis decoder 306 and constituent digital demodulator to begin processing the full paging channel for a second duration that is longer than the first duration. The control system 308 then monitors the data received on the full paging channel for a full page message directed to it and if no data is detected, the block deinterleaver 304 and trellis decoder 306 are deactivated and continue in standby mode. If a full page message is detected, control system 308 places the wireless terminal in an active mode during which the associated communication is performed.

In another embodiment of the present invention, the quick paging channel and the full paging channel are combined to the same code channel. I.e., the quick paging channel and the full paging channel are modulated with the same Walsh code. The quick paging channel and the full paging channel are logically distinguished by a predetermined time division scheme in the same code channel. For example, during some 80 millisecond time slots, quick paging messages are sent, while during other 80 millisecond time slots, full-speed paging channel messages are sent according to a predetermined slot allocation scheme. This implementation simplifies the receive and transmit processing by only requesting modulation or demodulation of a single code channel, but requires more efficient modification of the existing IS-95 standard, thus providing lower compatibility with existing IS-95 compliant wireless communication systems.

As is apparent from the description provided above, by employing quick paging message paging with a minimum number of bits and transmitted over a minimum code channel, the present invention allows the wireless terminal to consume less power than when monitoring for consumed messages during standby mode. Consuming less power in the standby mode allows the wireless terminal to operate longer on a given battery, thus extending the standby time of the wireless terminal. Since wireless terminals are typically used during mobile communications, timeouts are often required without recharging or replacing the wireless terminal's battery. Thus, to provide greater convenience and to reduce the likelihood of missing paging messages due to battery depletion, it is highly desirable to extend the standby time for a given battery.

Further, since the quick page message is sent in a highly reduced time, monitoring for quick page messages may be performed during active mode when telephone or other communications are handled in addition to standby mode. Such monitoring may be performed by simply suspending processing of the traffic channel to allow processing of the quick paging channel during the quick paging slot. Since the quick paging slot is approximately 5 milliseconds, any missing data is generally not missed or monitored and can be covered using Forward Error Correction (FEC) coding. Upon receipt of the quick page message, the full page message is received by sending a signaling message to the base station controller to further suspend processing of the traffic channel, followed by processing of the full page channel. Thus, the ability to receive paging messages during active mode is enhanced by employing the dual-event paging scheme described herein.

Thus, a dual channel method and system for reducing standby power consumption for paging cellular telephones and other wireless terminals is described. The previous description of the preferred embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without the use of the inventive faculty. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features described herein.

Claims (28)

1. A method for paging a wireless terminal, comprising the steps of:

a) generating a quick paging message;

b) generating a full page message, said quick page message containing less data than said full page message;

c) calculating the quick paging slot by using a first hash function for a MOBILE ID of the wireless terminal;

d) calculating the full paging slot by using a second hash function for the MOBILE ID; and

e) transmitting the full page message through a first code channel, transmitting the quick page message through a second code channel, the first code channel having a higher degree of coding than the second code channel, and the quick page message being transmitted during a quick page slot and the full page message being transmitted during a full page slot.

2. The method of claim 1, further comprising the steps of:

convolutionally encoding the full page message;

performing direct sequence spreading on the full paging message; and

and performing direct sequence extension on the quick paging message.

3. The method of claim 1, further comprising the steps of:

adding error detection information to said full page message;

performing direct sequence spreading on the full paging message; and

and performing direct sequence extension on the quick paging message.

4. The method of claim 1, further comprising the steps of:

interleaving the full page message;

performing direct sequence spreading on the full paging message; and

and performing direct sequence extension on the quick paging message.

5. The method of claim 1, further comprising the step of adding a delay between when said quick page message is sent and when said full page message is sent.

6. The method of claim 1, wherein the MOBILE ID is XOR'd with a function of the system time.

7. The method of claim 1, wherein said step c) is accomplished by using said first hash function for a system time and said MOBILE ID.

8. The method of claim 1, further comprising the steps of:

receiving the quick paging message;

starting a signal processing circuit; and

processing a full paging channel using the signal processing circuit.

9. The method of claim 8, wherein the signal processing circuit comprises a trellis decoding system.

10. The method of claim 8, wherein the signal processing circuit comprises a deinterleaver.

11. The method of claim 8, wherein the signal processing circuit comprises a cyclic redundancy check circuit.

12. A method for paging a wireless terminal in a wireless telecommunications system, comprising the steps of:

sending a quick page message over a low level code channel, said quick page message informing said wireless terminal to begin monitoring a high level code channel for full page messages; and

transmitting a full paging message through the advanced code channel;

the advanced code channel comprises a convolutional encoder, an interleaver and a modulator which are connected in series and are modulated by Walsh codes; and

the low level code channel includes a modulator that modulates data with a Walsh code.

13. The method of claim 12, wherein said quick page message contains less information than said full page message.

14. The method of claim 12, wherein the quick page message comprises a single data bit.

15. A method for paging a particular wireless terminal in a group of wireless terminals, comprising the steps of:

a) sending a quick paging message directed to a group of said group of wireless terminals, said group containing said particular wireless terminal, said quick paging message for directing said group to monitor an advanced code channel for full paging messages;

b) sending a full page message, said full page message identifying said wireless terminal;

the advanced code channel includes a series connection of a convolutional encoder, an interleaver, and a modulator that modulates with a Walsh code.

16. The method of claim 15, wherein step a) comprises transmitting said quick page message over a low level code channel during a first time slot assigned to said wireless terminal packet, said low level code channel including a modulator that modulates data with a Walsh code.

17. The method of claim 16, wherein step b) comprises transmitting the full page message during the second time slot allocated to the wireless terminal packet, wherein the second time slot occurs after the first time slot.

18. The method of claim 15, wherein the quick page message is sent over a low level code channel.

19. The method of claim 18, wherein the low level code channel is established by direct sequence modulation using a first channel code and the high level code channel is established by direct sequence modulation using a second channel code.

20. The method of claim 15, wherein said quick page message contains less information than said full page message.

21. The method of claim 12, further comprising the steps of:

generating the quick paging message; and

generating the full page message.

22. The method of claim 21, further comprising the steps of:

performing direct sequence spreading on the full paging message; and

and performing direct sequence extension on the quick paging message.

23. The method of claim 21, further comprising the steps of:

adding error detection information to said full page message;

performing direct sequence spreading on the full paging message; and

and performing direct sequence extension on the quick paging message.

24. The method of claim 21, further comprising the step of adding a delay between when said quick page message is sent and when said full page message is sent.

25. The method of claim 21, further comprising the steps of:

receiving the quick paging message;

starting a signal processing circuit; and

processing a full paging channel using the signal processing circuit.

26. The method of claim 25, wherein the signal processing circuit comprises a trellis decoding system.

27. The method of claim 25 wherein said signal processing circuit comprises a deinterleaver.

28. The method of claim 25, wherein the signal processing circuit comprises a cyclic redundancy check circuit.