ES2323992B1 - MULTI-USER WIRELESS ACCESS POINT FOR EXTENDED PICONET. - Google Patents

Abstract

Multi-user wireless access point for extended piconet .

According to the Bluetooth standard, a piconet consists of a master device and up to 7 slave devices.

The present invention extends this concept to ensure that a master device manages a large number of slaves in the same piconet .

The invention is formed by two controllers Bluetooth baseband, connected to two Bluetooth circuits radio and interconnected with each other and to a microcontroller, which manages the entire system, so that one of the controllers is finds permanently discovering other devices and the other establishes the connection with the discovered devices and performs communication tasks with these devices.

The invention also contains an operation method that allows obtaining optimum performance of the access point, improving the procedures for incorporating slave devices, managing access to the environment and abandoning the piconet .

Description

Multi-user wireless access point for extended piconet .

Technical sector

The invention is part of the field of personal area networks (PAN, Personal Area Networks), in multi-user environments, which use wireless technology in the ISM free band and, more specifically, the Bluetooth standard. The invention extends the concept of piconet (which in the Bluetooth standard allows up to 7 slave devices and one master) for the inclusion of a large number of slave terminals, which depends at all times on the environment conditions and reaches a technological limit above 200 users per piconet .

State of the art

The IEEE 802.15 (Bluetooth) specification has been become the standard of wireless voice communications and data followed by many manufacturers (more than 2000 companies are have adhered to it so far), there is great interest In its development. Bluetooth operates in the free part of the spectrum electromagnetic, specifically in the 2.4 GHz band, called ISM (Industrial, Scientific and Medical - Industrial, scientific and medical). Provides a short range wireless link (between 10 and 100 m), a speed of up to 1 Mbps and a consumption low enough to allow its use in portable electronic devices such as mobile phones and PDAs (Personal Digital Assistant), in the environment of the so-called wireless personal area networks (WPAN, Wireless Personal Area Networks). Local area networks Wireless (WLAN) usually operate at higher speed, from 10 to 100 Mbps, with a greater range and, for So much more consumption. Its use is common to connect laptops to a wired network through a point access (AP, Access Point). One of the best known standards is WiFi (802.11).

The Bluetooth SIG (Special Interest Group, Group of special interest) is an association formed by companies of recognized prestige in fields such as telecommunications, computer, automotive or industrial automation that promote the development of Bluetooth technology and boost its commercialization. It was founded in September 1998, being its Agere, Ericsson, IBM, Intel, Microsoft, Motorola, Nokia promoters and Toshiba, who have joined progressively as members multitude of associated and collaborating companies. November 2004 They have published version 2.0 of the standard.

Bluetooth initially emerged to replace wired short-range connections, such as that between a computer and a printer or between the headset and a mobile phone terminal when used as a hands-free. Currently it can be used to create ad-hoc networks of up to eight devices, one of which assumes the role of master and the others (up to seven) that of slaves. Each of these networks is called piconet and the same device can belong simultaneously to several piconet , allowing the interconnection between them, forming what is called a scatternet . The same device can be a slave in several piconets , but never master in more than one of them. A device belonging to several piconet can only send or receive data in one of them at a given time.

A Bluetooth system is composed of a radio unit, a link control unit and a unit of support for link management and interface with user applications Said system provides a connection point to point or point to multipoint. It is a transmission full-duplex that uses division techniques in the time, assigning slots of 625 microseconds of duration that they number consecutively, corresponding to those of numbering for master-slave communication and the odd ones to communication slave-master There is never direct communication Between two slaves

The Bluetooth transceiver is a radio system of spread spectrum that uses the frequency hopping technique over 79 channels, each with a bandwidth of 1 MHz. The jumps occur at a speed of 1,600 jumps per second, with a pseudo-random pattern that runs through the 79 channels, remaining the time corresponding to a slot (625 microseconds) in each channel.

The connection between two Bluetooth devices is initiated when one of them sends a connection request message (INQUIRY) to discover other devices that are active nearby. Any device that is in a listening state (INQUIRY SCAN) will recognize the message and can respond with a synchronization message (INQUIRY RESPONSE) with the necessary information to establish communication. This information includes the device's clock value and access code, a unique 48-bit address (IEEE 802) assigned by the manufacturer, called BD_ADDR. In addition, the piconet master device dynamically assigns a local address as an active, 3-bit member, called AM_ADDR and which is unique in the scope of the piconet . Each of the Bluetooth devices participating in a communication synchronize data exchanges with other devices using their own internal clock. The master device uses its internal clock to control the synchronization of the piconet . Slave devices synchronize with the master's clock by adding an offset value to their own internal clock.

The Bluetooth device that initiated the communication may be waiting to receive INQUIRY RESPONSE messages and thus collect the BD_ADDR information and internal clock value of other Bluetooth devices in the immediate vicinity. Once this data is known, you can send a PAGE message to establish communication with one of them, including in that message the Device Access Code (DAC) of the device with which you wish to establish communication. If this device is in PAGE SCAN mode, it will respond with an identical message and receive a Skip Frequency Synchronization (FHS) message from the master device, with the necessary information to establish communication. As soon as the slave device confirms its reception both devices go to the state of
Connection.

The INQUIRY and PAGE procedures are very well defined in the most recent version of the standard and constitute the necessary tools to form a new piconet or to add a slave to an existing one. However, there is no rule or procedure on its use. Once the devices found in the vicinity have been discovered, it is not possible to determine the optimal sequence of connections to follow to form the most suitable piconet in an efficient way. Piconets are formed more or less randomly, which leads to generally poorly optimal structures.

During the communication process, the master device transmits in the even slots and the selected slave responds in the odd ones. This relationship cannot be maintained if the master device has to send INQUIRY messages to detect the presence of new potential slaves, significantly compromising the effective data transfer speed in the piconet . Similarly, a master device can respond to an INQUIRY message from another device, becoming part of a second piconet as a slave and dividing its communication capacity and bandwidth between the two domains of which it is part.

It would therefore be desirable to have a mechanism that would improve the functioning of a master device to optimize the use of both  time slots dedicated to discovering new devices such as those intended for data communication between Bluetooth devices

For this, the present invention presents a novel design for an access point operating as a teacher and a method of operation of said access point that allows to divide device discovery tasks and communication between using two band controllers for that purpose Bluetooth base managed by a microcontroller and interconnected with each other and with said microcontroller in such a way that behave before other devices in the system communications as if from a single baseband controller Bluetooth will be. This achieves its total adaptation to Bluetooth standard and its compatibility with any device Existing Bluetooth

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Explanation of the invention.

The object device is described below. of the invention, whose main contribution is to improve in two fundamental aspects the characteristics and benefits of a Wireless access network based on Bluetooth technology. Both aspects that are improved are:

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Reduction in several orders of magnitude of access time to the data network of a device mobile that is incorporated into the coverage area of the point of access.

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Considerable enlargement (up to 30 times more) of the number of users that can access simultaneous to said access point.

The device object of the invention is an access point to wireless networks of Bluetooth technology that allows a computer system to act as a piconet master, in such a way that it accelerates considerably the speed of the incorporations of slaves to its piconet and at the same time greatly increases the number of these that can access simultaneously.

This access point behaves for all purposes, and regardless of its internal architecture, as if it were a standard Bluetooth controller that assumes the role of a piconet master. Any other Bluetooth device in the immediate vicinity can communicate with it in the same way as it would with a standard Bluetooth device.

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Internally, however, it has the elements described below:

to)

A Bluetooth baseband controller (1) (which we will call BT-1), in accordance with specifications V1.2 and V2.0, in the form of an integrated circuit (chip) configured to operate in continuous mode in MASTER INQUIRY mode (Bluetooth specification V2.0 Volume 2 Part B. Chapter 8)

b)

A Bluetooth baseband controller (2) (which we will call BT-2), in accordance with specifications V1.2 and V2.0, in the form of an integrated circuit (chip) configured to operate alternatively and sequentially in PAGE and CONNECTION mode (Bluetooth specification V2.0 Volume 2 Part B. Chapter 8)

C)

Two integrated circuits Bluetooth radio (3, 4) (according to the Bluetooth specification V2.0 Volume 2 Part A) operating according to class 2 specifications, independently connected to elements a) and b) above respectively through a interface conforming to the Bluetooth Blue RF specification Working Group and connected to two antennas (8, 9) for transmission and reception.

d)

A communications port conforming to the USB specification (5) for connection with a computer system.

and)

An integrated microcontroller circuit (6) connected to elements a), b) and d) by means of a standard industrial communications bus (7) (SPI; UART, I2C, GPIO or USB) and in charge of executing a control procedure for all system to allow the final communication of the application executed in the computer system with the applications executed in the potential Bluetooth devices accessible in the piconet .

The communications bus is responsible for the two controllers are fully interconnected baseband (BT-1 and BT-2) and these with The microcontroller It is said microcontroller that will send the necessary information to BT-1 and BT-2 so that your internal clocks are perfectly synchronized and to use the same identification of device in messages sent through their respective Bluetooth radio integrated circuits. In this way, to a Bluetooth device located nearby and detect a wireless message issued by the access point you it will be impossible to distinguish if the message comes from BT-1 or BT-2 and may not even appreciate that the messages come from two different devices. Thus, the access point behaves, facing the outside, as if it were a single Bluetooth device.

The microcontroller also ensures that BT-1 and BT-2 behave according to the correct operating procedure. In this way, it executes the necessary instructions so that BT-1 is permanently in MASTER INQUIRY mode and so that BT-2 works alternately in PAGE and CONNECTION mode. The microcontroller communication with BT-1 and BT-2 is done through an HCI interface according to the Bluetooth specification so that the first one is dedicated to the work of discovering other Bluetooth devices while the other manages the establishment and release of connections of the devices included in the piconet .

Through this novel mechanism of dividing the tasks of incorporating slaves into a piconet and of master-slave communication, the procedures for incorporating slave devices are expedited, without interrupting the exchange of information within the piconet , since Frequency sequences used for both roles are different. Thanks to this, it is possible to significantly increase the number of slave devices simultaneously incorporated into a piconet and substantially reduce the access time to the data network of a slave device incorporated into the coverage area of the multi-user access point.

Finally, the microcontroller will handle communicate Bluetooth controllers with a computer system to through the USB port that incorporates the access point multi-user

Regarding the method of operation of the multi-user access point for extended piconet , we can consider three main types of procedures: the one corresponding to the incorporation of slave devices to the extended piconet , the person in charge of managing access to the shared medium and the procedure of abandonment of the network by slave devices.

1. Procedure for incorporating slave devices to the extended piconet

The Bluetooth baseband controller BT-1 remains constantly in the state of INQUIRY, in such a way that it sends ID packets in the slots of transmission using frequency hopping sequence defined for such procedure (Bluetooth Specification Version 2.0, Volume 2, part B, section 2.6). In these transmissions the The access code used is the General Inquiry Access Code (GIAC) and the frequency hopping sequence is derived from the GIAC itself and of the Bluetooth controller clock.

BT-1 listens in the reception time slots for possible FHS packets sent by slaves in the INQUIRY SCAN state, and informs the microcontroller of the results received by means of an INQUIRY RESULT EVENT (Bluetooth Specification Version 2.0, Volume 2, part E, section 7.7.2), fundamentally extracting the BD_ADDR address information and the slave clock offset . Then the BT-1 controller will continue with the same discovery process in INQUIRY state.

With the information provided by BT-1, the microcontroller requests the BT-2 Bluetooth baseband controller to establish a connection with said slave, passing BT-2 to the PAGE state and suspending its usual activity, which will be the transmission of the data of the final application between the devices of the piconet .

Then BT-2 and the slave detected carry out the establishment procedure communication defined in the Bluetooth specification (Bluetooth Specification Version 2.0, Volume 2, part B, section 8.3). BT-2 sends a PAGE message, via a packet ID using the sequence break defined for PAGE (Bluetooth Specification Version 2.0, Volume 2, Part B, Section 2.6.4.2) with the estimate of the slave clock provided by the microcontroller and using derivative access control (CAC) of the slave's BD_ADDR.

The slave will answer with an ID package that does the BT-2 controller goes to MASTER state RESPONSE, in which you will send an FHS packet to the slave which, in turn, among other things, determine the LT_ADDR address that will identify to the transport link that will be used in the state of CONNECTION For its part, the slave will nod with a package ID.

From this point both devices enter in CONNECTION state, using the jump sequence of basic channel frequency derived from the BD_ADDR and the clock of the Master (Bluetooth Specification Version 2.0, Volume 2, Part B, section 2.6.4.7) and the access code (CAC) of the channel that It is derived from the BD_ADDR address of the master.

At this point, a shipment of a POLL package by the master and any response by the slave will close the connection establishment cycle between them. From said moment BT-2 will communicate to the microcontroller a full connection event and it will store connection data established.

The microcontroller will take care immediately to identify the connection established with the new slave user and send you a PARKED order, using it to BT-2 Then the microcontroller communicate, to the driver of the computer system to which it is connected, the information corresponding to the new user and the availability of a non-connection oriented service for data transmission.

2. Procedure for managing access to the environment shared

The microcontroller of the access point will also be responsible for executing a layer of protocols for access control to the shared medium, whose functionality is to organize access to the shared transmission medium for more users of simultaneous operation than specified by the standard Bluetooth, constituting an extended piconet .

To do this, all the slaves of the piconet in PARKED state will be placed immediately after connection with them is established by means of an HCI_Park_State command addressed to the newly connected slave through the BT-2 controller. Subsequently, the activity of the BT-2 controller will be carried out as follows:

The BT-2 controller establishes a soda cycle of parked slaves in which time between moments beacon (TB) is distributed between a time of small beacon (Daccess) frame transmission and a time of Access windows (Taccess) enough to listen to the requests from each slave (1 slot of 625 \ musg. per each slave). At the end of the access window you can know all existing requests that would be read below by the mechanism of disappearing, reading and parking, which would occupy 5 msg per slave questioned.

This mechanism behaves optimally in environments where there are many slaves that generate little traffic.

There is an alternative mode of operation, more efficient when there are few slaves that generate a lot of traffic of data:

The BT-2 controller establishes a cycle of beacon slots in which, for each beacon frame, it is unpacked, interrogated and parked again to each of the slaves. 8 basic Bluetooth slots (5 msg in total) are required for each slave for a message reading capacity of up to 123 characters with FEC protection against errors (DM-3 packages) or 185 without protection (DH3 packages).

The decision to use one or the other protocol in the same session is taken by a software entity of this same access management layer for adaptation of Bluetooth technology and communicated to the slaves by means of LMP_set_broadcast_scan_window and LMP_modifjy_beacon packets transmitted through the PSB-C logical link .

Reliability and protection against errors that used is the one offered by the transport protocol Bluetooth

3. Network abandonment procedure

The procedure for detecting the abandonment of a network user is that central microcontroller checks in your slave identification table those who have exceeded a sufficiently large configurable time without activity (from minutes order) and instructs the BT2 controller to unpack interrogate the slave terminal not very active. If there is no answer, the BT-2 communicates it to the microcontroller that will remove from your connection table and in turn communicate it to driver of the computer system to which it is connected. As already commented, this mechanism behaves optimally in environments where there are many slaves that generate little traffic.

For the alternative mode of operation, that is, in the case that there are few slaves that generate a lot of data traffic, there is also an alternative procedure for abandoning the network that will be more efficient, and that is that the microcontroller will take into account the lack of response by a terminal in a successive number of times, by means of a counter associated to each terminal with the number of times it has not responded in the interrogation procedure for data traffic described in the previous section. When said counter reaches a set value that is sufficiently large, it will be considered that the terminal has left the piconet , it will be removed from the microcontroller connection table and the discharge will be communicated to the computer system driver.

Description of the drawings

A diagram with the different elements that form the multi-user access point for extended piconet object of the present invention is shown in Figure 1.

The multi-user access point consists of following items.

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A baseband controller Bluetooth (1), called BT-1 Controller in the Figure 1.

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A baseband controller Bluetooth (2), called BT-2 Controller in the Figure 1.

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A Bluetooth integrated circuit radio (3), called Bluetooth Radio 1 in Figure 1, connected to BT-1 through an interface conforming to the Blue RF specification of the Bluetooth Working Group and connected in addition to its own antenna (8) suitable for transmission and reception in the ISM band.

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A Bluetooth integrated circuit radio (4), called Bluetooth Radio 2 in Figure 1, connected to BT-2 through an interface conforming to the Blue RF specification of the Bluetooth Working Group and connected in addition to its own antenna (9) suitable for transmission and reception in the ISM band.

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An integrated circuit microcontroller (6), called Microcontroller in the Figure one.

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A communications bus (7), with the associated circuitry necessary to interconnect the Microcontroller (6) with BT-1 (1) and BT-2 (2) and these between M.

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A communications port (5), with the necessary associated circuitry, called USB port in the Figure 1, which serves as a connection point between the Microcontroller (6) and an external computer system and that can be a USB port or of any other type.

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A flow chart is shown in Figure 2 which describes the method of operation of the controller BT-1, which consists of continually staying in the MASTER INQUIRY state.

Thus, BT-1 sends an INQUIRY message with ID packets in the transmission slots and listens to the reception time slots. If you receive a response within a specified period of time, you will send an INQUIRY RESULT EVENT message to the Microcontroller, which will contain the necessary parameters of the device that responded to your message. After sending said message to the Microcontroller, or in the event that the specified deadline expires without receiving any response, it will send an INQUIRY message again, repeating the
cycle.

A flow chart describing the operation method of the BT-2 controller for incorporating slave devices into the piconet is shown in Figure 3. BT-2 will be in CONNECTION mode using the procedure represented in Figure 4 (or, for the alternative embodiment of the invention, the procedure shown in Figure 5) until a request for connection establishment with a new one is received from the Microcontroller slave device

At that moment BT-2 goes to PAGE mode to carry out the procedure for setting communication defined in the Bluetooth specification and described with anteriority. If the procedure is completed successfully, BT-2 sends an event of the Microcontroller Full connection with the data obtained in the process. TO then the microcontroller identifies the connection established and instructs BT-2 to Park the new slave. From this moment, BT-2 resumes its communication activity happening to CONNECTION mode.

If the procedure for establishing communication is not successful, BT-2 reports this circumstance to the Microcontroller, also going to mode CONNECTION

A flow chart is shown in Figure 4 which describes the method of operation of the controller BT-2 in CONNECTION mode.

BT-2 establishes a cycle of soda for parked slaves with a small beacon frame transmission time and sufficient access window time to listen to the requests of each of the slaves. At the end of the access window all existing requests are known.

From that moment on, read each one of the requests received, following the procedure of unpacking a slave with a pending request, interrogate it and return it to Park.

When there are no pending requests to attend, BT-2 will establish a refresh cycle again. This procedure will be interrupted each time the Microcontroller asks BT-2 to perform the communication establishment procedure, described in Figure 3, to incorporate a new slave to the piconet .

A flow chart is shown in Figure 5 which describes the alternative operation method of the controller BT-2 in CONNECTION mode, which is more suitable for environments with few slaves that generate a lot of traffic of data.

Initially, BT-2 will not take any action until a slave device has been incorporated into the piconet . Once there are slave devices, which are in PARKED state (as seen in the description in Figure 3), BT-2, always following the instructions of the Microcontroller, establishes a beacon slot cycle in which, for each slot , unpark, interrogate and park each of the slaves again. For each slave you need 8 basic Bluetooth slots.

This procedure will end when there are no slaves in the piconet and it will be interrupted each time the Microcontroller asks BT-2 to perform the communication establishment procedure, described in Figure 3, to incorporate a new slave into the piconet .

Embodiment

The present invention is further illustrated. with the following embodiment example, which is not intended to be limiting its scope.

The main board consists of an interface of USB communication with a computer, a power outlet mains power, a power indicator LED and two connectors MMCX for antennas.

Internally the main circuit board will house the voltage conversion circuitry suitable for the electronic systems power, taking care fundamentally to avoid possible curling and coupling of noise with other systems through filters and elements of isolation.

The main part of the system, where the intelligence of the access point is located, will be a microcontroller with a USB port directly connected to the USB bus for communication with the computer where for example a monitoring application of the Bluetooth devices that access the piconet On the other hand, the microcontroller will maintain communication and control over the BT-1 and BT-2 Bluetooth baseband controllers through two 12C buses.

Finally, each controller will communicate through a Blue RF bus with an integrated Bluetooth Radio circuit, which at its once it will end in an external MMCX connector where to connect the connection of the antennas, which will allow them to be arranged in a most suitable position for transmission and reception in each concrete installation, regardless of where the computer equipment and where the access point is housed.

Claims (3)

1. Access point for wireless networks of Bluetooth technology, operating as a Piconet Master in which the limitation of 7 slave users established by the Bluetooth standard is exceeded, characterized in that it contains:

to)

A Bluetooth baseband controller (1) (BT-1), conforming to the Bluetooth standard, configured to operate in continuous mode in MASTER INQUIRY mode.

b)

A Bluetooth baseband controller (2) (BT-2), conforming to the Bluetooth standard, configured to work alternatively and sequentially in PAGE and CONNECTION mode.

C)

Two integrated circuits Bluetooth radio (3, 4) (according to the Bluetooth specification, connected independently and respectively to elements a) and b) above, through an interface compliant with the Blue RF specification of the Bluetooth Working Group and connected each of them to its own antenna (8, 9) of transmission and reception

d)

A communications port (5) for connection to a system external computer

and)

A integrated microcontroller circuit (6), connected to the elements a), b) and d) via a communications bus (7), in charge of execute a system wide control procedure for:

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\ vtcortauna Carry out the communication of the application executed in the computer system with the applications executed in the potential Bluetooth devices accessible in the piconet .

?

\ vtcortauna Control and manage the behavior of BT-1 and BT-2.

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\ vtcortauna Ensure that at all times BT-1 and BT-2 share the clock synchronization signal so that both act as a single master device.

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\ vtcortauna Manage that BT-1 and BT-2 share the information used by each of them.

2. An access point operation method declared in Claim 1 characterized in that it comprises the following operations:

to)

He BT-1 baseband controller is maintained constantly in the state of INQUIRY, sending ID packages in the transmission slots using the hop sequence of frequency defined in the Bluetooth specification, using to this is the access code GIAC (General Inquiry Access Code), of so that the sequence of frequency hops is derived from the own GIAC and the communications controller clock.

b)

Saying BT-1 controller listens in the time slots of Reception of possible FHS packets sent by other devices Bluetooth that are in INQUIRY SCAN state, and informs the microcontroller of the results received through an INQUIRY RESULT EVENT, according to the Bluetooth specification, extracting, at least the information of the BD_ADDR address and the offset of the slave clock. Next the communications controller will redo the same discovery process in state INQUIRY

C)

With this information, the microcontroller asks the BT-2 baseband controller to establish a connection with the discovered Bluetooth device, passing said BT-2 controller to the PAGE state, suspending its usual activity, which will be the transmission of data from the final application between the devices of the piconet .

d)

TO then the baseband controller BT-2 send a PAGE message to the Bluetooth device detected by an ID packet, using the sequence break defined for PAGE in the Bluetooth specification, with the clock estimate of the Bluetooth device detected provided by the microcontroller and using the access control (CAC) derived from the BD_ADDR of the Bluetooth device detected.

and)

When the Bluetooth device detected answer with an ID package, the baseband controller BT-2 goes to MASTER RESPONSE state, in which it sends to the Bluetooth device detected an FHS package which, in turn, among other things, determine the LT_ADDR address that identifies the transport link to be used in the CONNECTION state. By on its part, the detected Bluetooth device will nod with a ID package

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F)

TO from this point both devices enter CONNECTION status,  using the basic channel frequency hopping sequence derived from the BD_ADDR and the baseband controller clock BT-2 and the channel's own access code (CAC), which is derived from the BD_ADDR address of the band controller BT-2 base. In this connection thus established, the BT-2 baseband controller plays the role of master and the Bluetooth device detected that of slave.

g)

A Once in CONNECTION status, a shipment of a POLL package by the master and any response by the slave will close the cycle of establishment of connection between both. From that moment BT-2 baseband controller communicates to microcontroller a full connection event, which handles to store the data of the established connection.

h)

For each slave incorporated into the piconet , the microcontroller will immediately order its passage to the PARKED state using the BT-2 baseband controller, which will send an HCI_Park_State command to the newly connected slave. At that time, the microcontroller communicates, to the driver of the computer system to which it is connected, the information corresponding to the new user and the availability of a non-connection oriented service for data transmission.

i)

The microcontroller will configure access to the shared medium and the exchange of data between the multi-user access point and the slaves built into the piconet by sending the LMP_modify_beacon package via the PSB-C logical link according to the Bluetooth specification. With this, the BT-2 baseband controller will perform a refresh cycle of the parked slaves in which the time between BEACON (T_ {B}) instants is divided between a small BEACON (Daccess) frame transmission time and a time of access windows (Taccess) sufficient to listen to the requests of each slave (1 slot of 625 \ musg. for each slave). At the end of the access window, all existing requests will be known, which are then answered sequentially, by means of the disappear, read and park mechanism, according to the Bluetooth specification.

j)

He microcontroller will manage the abandonment of the network by the slaves, ordering the baseband controller BT-2 that interrogates directly to a terminal slave who exceeded some time without communication activity, checking in that case whether or not it continues in the coverage area of the master to, if necessary, remove it from the terminal list slaves and notify the computer driver.

3. A method of operation of the multi-user access point according to Claim 2, preferably used when there are few slaves that generate a lot of traffic, characterized in that:

?

The microcontroller will configure access to the shared medium and the exchange of data between the multi-user access point and the slaves built into the piconet by sending the LMP_set_broadcast_scan_window package via the PSB-C logical link according to the Bluetooth specification. With this, the BT-2 baseband controller establishes a BEACON slot cycle in which, for each BEACON frame, it unpacks, interrogates and parks each of the slaves again, according to the Bluetooth specification.

?

The method used for management of network abandonment by slaves includes the microcontroller's decision that a slave terminal has abandoned the network if you don't get any response from that slave a certain number of consecutive times for, in this case, remove it from the list of slave terminals and notify it to computer driver