RU2350024C1 - Method of allocation of time intervals in radio communication network channels - Google Patents

Abstract

FIELD: information technologies.

SUBSTANCE: in the known method of allocation of time intervals in a temporary frame where network stations are authorised to transmit and accept the information, recording of user's stations then broadcast is authorised to the registered user's stations only on demand of the central station that allows to provide lack of collisions of transmissions of the registered user's stations is entered; besides, the central station carries out allocation change to the active user's stations without a disrupture of linkings, and also maintains the oozed allocation without dependence from activity of transmissions. Thus the central station carries out an error analysis in accepted packages of the information and the solution on the further transmission of the spoilt packages according to a degree of importance of the transmitted information passes.

EFFECT: unjammable and trusty establishment of linkings in system from several networks, granting to the subscriber of the guaranteed resource during the long-term time interval.

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Description

The invention relates to the field of radio engineering and may find application in information transmission systems composed of several wireless networks.

A known method of distributing radio resources in a system of multiple wireless networks, described in US patent No. 6650655; 370/468 "Allocation of data transmission resources between different networks", 2005, in which the efficiency of the use of system resources is provided by the dynamic allocation of resources to individual networks of the system based on the assessment (measurement) of download statistics in individual network systems. At the same time, partially overlapping resources are allocated to networks with low subscriber activity. The disadvantage of this method is the probability of collisions of calls and transmissions due to the reuse of frequencies by different networks of the system. Since the load estimate and the corresponding resource allocation commands are always behind the current moment, the probability of collisions can reach large values, which is acceptable in a conventional computer network, but is undesirable in systems for the exchange of special information critical for time delays.

A known method of allocating time slots in a system with a dynamic time division multiple access (TDMA) system, as described in US Pat. No. 6,445,701; 370/368 "Channel access scheme for use in network communications", 2002, in which the communication channel is divided into frames, each frame is divided into slots and then the slots are divided into mini-slots . In this case, the first slot is divided into many mini-slots for transmitting connection requests from communication sources. The second slot is divided into two subsets of mini-slots, where the first subset of mini-slots is allocated to increase the resources of existing video connections, and the second subset of mini-slots is reserved for connection requests from communication sources. The volume of the first subset of mini-slots may vary depending on the number of installed video connections; the algorithm for this change is, in fact, the subject of the invention of this patent. The third slot is reserved for reception by the router (base station) of service messages from sources having established connections.

The disadvantage of this method is that the time intervals (mini-slots) allocated for transmitting requests for establishing a connection from communication sources in the direction of the router are used by random communication sources of communication. With a high activity of communication sources, the number of collisions of transmissions increases, which leads to difficulties or even the inability to establish new connections.

The closest in technical essence to the proposed method is the method described in US patent No. 5371734, H04B 007/216: H04B 007/26 "Medium access control protocol for wireless network" (1994, adopted as a prototype.

The prototype method is as follows. One of the radio stations on the network is assigned to operate as a central (base) station. Using the base station, access control to the channel is carried out for the remaining radio stations of the network, which are subscriber stations. In the base station, a temporary frame is formed to regulate the broadcasting intervals of subscriber stations. The structure of the time frame is set as follows. At the beginning of the time frame, a first interval is allocated for transmitting the synchronization signal and overhead information from the base station to the subscriber stations. Then, a second interval is allocated for transmitting broadcast information from the base station to the subscriber stations (sent to all subscriber stations of the network). Then, a third interval is allocated for the targeted transmission of information from the base station to one or more subscriber stations. Then, a fourth interval is allocated for retransmission of overhead information from the base station to the subscriber stations. Then, a fifth interval is allocated for receiving by the base station information from subscriber stations. In this case, the fifth interval is divided into slots that are distributed to subscriber stations. Distribution commands are transmitted to subscriber stations in the first and fifth intervals as part of overhead information. Then, a sixth slot is allocated for the base station to receive distribution requests from subscriber stations. At the end of the frame, a seventh interval is allocated for exchanging information with neighboring networks.

At the physical level, information in the prototype method is transmitted using direct-sequence spread spectrum signals, using binary or quadrature phase shift keying.

During the first time frame interval in the base station, the synchronization signal is generated and broadcast, followed by service information for the subscriber stations. This overhead information includes information on dividing the frame into intervals, allocation of intervals for receiving and transmitting information to those subscriber stations that sent requests in the previous frame, and also the position in the frame of the interval for transmitting requests to subscriber stations that do not have a distribution. The subscriber stations receive the signal of the base station, synchronize their receivers and allocate service information about the distribution of each subscriber station intervals for reception and transmission. In the future, subscriber stations can turn off the power of their receivers and transmitters at intervals where this subscriber station is not allowed, respectively, to receive or transmit information. Subscriber stations that do not have a distribution synchronize their receivers, extract service information, in particular, the temporary position of the request interval, and wait for the start of the request interval to transmit distribution requests in the direction of the base station.

During the second time frame interval, all subscriber stations receive broadcast information from the base station.

During the third time interval, information is received only by subscriber stations that have received a distribution for receiving information during the first interval in a given time frame.

During the fourth time interval, the base station retransmits overhead information, and the subscriber stations specify their respective distributions.

During the fifth interval, the subscriber stations accordingly generate signals for transmission and transmit them in the direction of the base station in the slots allocated to them. Since the distribution of slots for a particular subscriber station can operate for several frames in accordance with the request, the base station monitors the use of subscriber stations allocated slots. If the subscriber station does not use the slots allocated to it, then in the next frame, the base station cancels the distribution of this subscriber station in favor of the station that sent the distribution request.

During the sixth time interval, subscriber stations that have established synchronization with the base station but do not have a distribution transmit distribution requests in the direction of the base station. The base station receives request signals from subscriber stations and, if there is a free resource, transmits a new distribution as part of overhead information in the first interval of the next time frame.

During the seventh interval, the base station of the network transmits a beacon for the base station of the neighboring network. This beacon contains information about the characteristics of the base station. The base station of the neighboring network receives a signal from the first base station and transmits a response frame to the beacon signal to the first base station during the seventh interval. The beacon response frame contains information about the characteristics of the base station of the neighboring network. Moreover, the base stations of neighboring networks exchange transmissions in one predetermined radio frequency channel, which differs from the radio frequency channels that the first and second base stations use for radio communication with their subscriber stations.

Base stations of neighboring networks exchange transmissions using direct-sequence spread spectrum signals, using code sequences that are different from code sequences used for exchanging within a network between a base station and subscriber stations.

Despite the use of a separate radio frequency channel and separate code sequences for exchange between base stations, base stations of neighboring networks adjust their transmission cycles relative to each other and exchange packets during the seventh interval of the communication cycle.

When transmitting a distribution request, each subscriber station reports information about its physical characteristics to the base station. The base station compares this information with its characteristics and, if the new subscriber station in the network is better equipped, the base and subscriber stations begin the transfer of control in the network from the base station to the subscriber. An example of such a characteristic can be the power supply of the station from the mains or from batteries.

Subscriber stations in the network transmit with modules containing many frames, while in the module header there is at least one field containing information about at least one frame that was not successfully received during the previous transmission module. In response to this, the central station repeats said frames in the next transmission unit.

But the prototype method has a significant drawback, namely, that time intervals for connection establishment requests are used by subscriber stations according to the random access principle, which leads to a large number of transmission collisions with large activity of subscribers and makes it difficult to establish new connections. In addition, the prototype method does not guarantee the subscriber the distribution of the required resource for a long period of time, since the central station cancels the distribution according to the results of monitoring the channel usage by the subscriber station and can cancel the distribution before the end of the transmission.

Thus, the disadvantages of the prototype method are the low noise immunity of the establishment of connections and the inability to guarantee the provision of a channel of the required quality for a long period of time.

To eliminate these shortcomings in the method for allocating time intervals in radio communication network channels, including assigning one of the network stations as a central station, on the central station side, dividing the communication channel into time frames, transmitting a synchronization signal, dividing time frames into time intervals, where network stations are allowed to transmit and receive information, distribution to subscriber stations of temporary sub-intervals (slots), where each subscriber station can transmit and receive information, exchange of transmissions with the central station of another network of this system in a frequency band different from the frequency band in which the subscriber stations of this network operate, and on the side of the subscriber station, establishment of synchronization with the central station, reception and allocation of service information on the distribution of time intervals for transmission and receiving packets of user information, receiving packets of user information in accordance with the distribution of time intervals and transmitting packets of user information in According to the invention, according to the invention, in the time frame of the central station, after transmitting the synchronization signal, a time interval is allocated for transmitting service information packets from the central station to subscriber stations, then a time interval divided into time slots is allocated for transmitting user information packets from the central stations to subscriber stations, then allocate a time interval for registration of subscriber stations, then allocate a time interval, under divided into temporary slots for receiving service and user information packets from subscriber stations in accordance with the slots allocated to them, while on the subscriber station side, synchronization with the central station is established, service information packets are received from the central station during the entire transmission interval of service information and allocate commands addressed to them to open service channels; on the side of the subscriber station, which is broadcasting for the first time, after establishing synchronization with the signal of the central station, during the registration interval a packet with the identifier is sent in the direction of the central station and waiting for commands to open the service channel from the central station; on the side of the central station, a packet with an identifier is received from the subscriber station during the registration interval and, in the interval for transmission of service information packets, in subsequent frames, commands are sent to open the service channel of the subscriber station, the identifier of which was successfully received; on the side of the subscriber station that has received commands to open the service channel, service information packets are transmitted in the time slots allocated to it; on the side of the subscriber station that transmitted the identifier but did not receive commands to open the service channel, the identifier is repeated in the registration interval of the next randomly selected frames; on the side of the central station, service polling packets are periodically transmitted in the direction of registered subscriber stations, opening service channels for transmitting responses to polling packets and, if necessary, distribution requests from registered subscriber stations; on the side of the central station transmit service information packets with commands to open channels for transmitting packets of user information from subscriber stations requesting distribution; on the side of the central station, packets of user information are received from subscriber stations in the time slots allocated to them for one or more frames; on the side of the central station, periodically optimize the use of time intervals in the frame, while the active subscriber station allocates a new distribution and continues to receive signals on the old distribution until communication is established on the new distribution, after which the channel is closed on the old distribution; on the side of the central station, close the channel for transmitting user information packets by the corresponding message from the subscriber station or in the absence of a response from the subscriber station to a given number of polls; on the side of the central station, they analyze erroneously received information packets according to the importance of messages (speech, video, data) and transmit to the addressee error-free and spoiled packets with information of the lowest degree of importance (speech, video) and only error-free packets of information of the highest degree of importance (data); in addition, from the central station, radio is exchanged with the central station of another network that is part of the system, regardless of the time frames of its network.

The proposed method for the distribution of time intervals in the radio communication network channels is as follows.

One of the radio stations on the network is assigned to operate as a central (base) station. With the help of the central station, access control to the channel is carried out for the remaining radio stations of the network, which are subscriber stations. In this case, the radio exchange between subscriber stations is conducted through the central station using the time division multiple access (TDMA) method: the communication channel is divided into time frames, which are divided into time intervals (slots), where network stations are allowed to transmit and receive information. The formation of a temporary frame occurs in the central station.

The structure of the time frame is set in accordance with the time chart presented in figure 1. At the beginning of the time frame, the T1 interval is allocated for transmitting the synchronization signal and the network identifier.

Then, a time interval T2 is allocated for transmission of service and user information packets from the central station to the subscriber. Interval T2 is divided into two sub-intervals: T2 ₁ - for transmitting “down” packets of service information to all registered stations and T2 ₂ - for transmitting “down” packets of user information to active subscriber stations.

Then allocate a time interval T3 for registration of subscriber stations.

Then, the time interval T4 is allocated for upstream transmission of service and user information packets from subscriber stations to the central station. Interval T4 is divided into sub-intervals T4 _k , which are allocated to individual subscriber stations. Between the subintervals T4 _k , small guard intervals are provided to prevent transmission overlay due to different propagation times of signals from different subscriber stations.

During T1, the central station transmits a synchronization signal and a network identifier. These signals can, for example, be transmitted using noise-tolerant broadband modulation. The duration and code structure of the synchronization signal are selected in accordance with the requirements of ensuring noise immunity of the communication network.

Subscriber stations receive a synchronization signal, synchronize their receivers and wait for the arrival of service packets from the central station. During the time interval T2 _1, subscriber stations extract headers of service information addressed to them from the general stream.

During T2 _2, subscriber stations having open information channels receive user information packets in the T2 _2.k intervals allocated to them.

During T3, the first-time subscriber stations broadcast a short service registration packet, which contains only the identifier of this subscriber station. Moreover, the subscriber station begins the registration procedure in the network, regardless of whether it has a packet queue for transmission. If the central station has successfully received the packet with the identifier, the registration procedure of the subscriber station begins. The central station compares the received identifier with a list of possible network subscribers and a list of registered network subscribers. If the subscriber station is recognized normally, then the corresponding commands for opening the service channel are sent to its address: in the T4 interval, a short time interval is allocated for the transmission of service information packets from the subscriber station to the central one.

If there is a problem identifying the subscriber station, the central station sends a registration failure. The reason for registration failure may be an incorrect subscriber station identifier or the presence of an already registered station with this identifier. Both situations are taken as an attempt to unauthorized access to the network.

After receiving commands to open the service channel, the subscriber station transmits service packets containing the information necessary for registering on the network. Such information may be authentication data (access codes), types of equipment connected to the subscriber station, and subscriber numbers of this equipment. For example, phone, fax, etc.

After the registration procedure, the service channel is closed, and the subscriber station continues to wait for service packets sent to it from the central station. This subscriber station will no longer go on the air on its own initiative, except in the event of a possible loss of network and the need for re-registration.

The subscriber station that transmitted the packet with the identifier, but did not receive a response, repeats the transmission of the packet with the identifier during the registration interval T3 of one of the following frames, and the choice of the frame is determined by the pseudo random number sensor.

The central station periodically polls registered subscriber stations. The interrogation procedure consists in the fact that the central station opens service channels for registered subscriber stations and awaits responses to interrogation service packets. If the subscriber station has information to transmit (requests to open the channel from equipment connected to the subscriber station, etc.), it transmits them in the open service channel before responding to the service survey packet. If the subscriber station does not have information to transmit, it transmits a polling response packet to the central station.

If in the polling procedure the subscriber station requested the opening of the information channel from the central station, the central station sends service packets to the subscriber station address with the intervals T2 _2.k allocated to it (one of the sub-intervals T2 _2.1. -T2 _2.n ) for reception and T4 _k (one of the sub-intervals T4 ₁ -T4 _n ) - for transmission. The subscriber station confirms the receipt of the distribution by the beginning of work in the interval T4 _k allocated to it. The number and duration of time slots allocated to the subscriber station for reception and transmission is determined by the central station depending on the transmission speed requested during the exchange of service packets.

The polling frequency of each subscriber station depends on the number of registered stations in the network: the fewer stations are registered, the more often they are polled.

Thus, the connection establishment procedure in the proposed method is carried out in two stages: first, registering the subscriber station in the network, then periodically polling the registered subscriber stations, the results of which open a channel for transmitting information if the subscriber station has a queue of packets for transmission. Moreover, in the unregulated registration interval T3, only the subscriber station identification number is transmitted. All other service messages related to the registration of the subscriber station and channel allocation procedures for transmitting information packets are transmitted at intervals specially allocated by the central station.

During the interval T4, subscriber stations having open information channels transmit service and user information packets in the time intervals T4 _k allocated to them. Each subscriber station fills out the time interval T4 _k allocated to it as follows: first, a short synchronization sequence is transmitted, then service information packets, then user information packets until the end of the T4 _k interval. Service information packets may contain response messages to commands of the central station, as well as requests for additional distribution or cancellation of the existing one.

For example, a subscriber station AC1 has an open telephone channel with a subscriber station AC2 (through a central station). Suppose, during telephone conversations, it becomes necessary to transmit video information or data from AC1 to AC1 through the RS-422 port. In this case, AC1 sends a corresponding request to the central station and the central station starts the distribution change procedure, which is as follows. The central station sends service information packets towards the subscriber station with commands to open the channel on the new distribution and maintains the channel on the old distribution until a signal is received from this subscriber station on the new distribution.

A procedure is also provided for changing the distribution without expanding the channel volume — optimizing the use of time intervals in the frame. Since the channel constantly opens and closes channels to various stations, the T2 ₂ and T4 intervals become fragmented: random alternation of the free intervals T2 _2.k and T4 _k filled with transmissions. To increase the efficiency of using time intervals, the central station periodically makes a shift to the beginning of the interval T4 of the sub-intervals T4 _k and a shift to the beginning of the interval T2 of the ₂ sub-intervals T2 _2.k allocated to subscriber stations, i.e., change procedures are started for transmitting and receiving information of subscriber stations distribution. Each of these subscriber stations receives a new distribution as part of the service information and is tuned to transmit and receive in new time slots at the nearest point in time convenient for the given subscriber station. At the same time, the central station supports both distributions before receiving a signal of a given subscriber station in a new time slot. Only after establishing the channel on the new distribution, the central station closes the old distribution. Thus, when changing the distribution, the connection is not interrupted, the subscriber does not lose data.

The subscriber station that has received the distribution retains the open channel of the allocated volume until it itself requests the procedure for closing the channel. At the same time, the central station does not reduce the volume allocated to this subscriber distribution station even in the case of weak transmission activity. To close the channel, the subscriber station transmits the corresponding service packet at the beginning of its T4 _k interval and continues to transmit information until the end of this interval.

In the proposed method, there are only two cases of canceling the distribution on the initiative of the central station, since in real conditions there are hardware failures or deliberate failure of the subscriber (in military applications). When the central station polls its group of registered subscriber stations (passive and active) and receives response messages, it thereby collects information about the health of its subscribers. At the same time, several reply messages are allowed to be skipped. For example, the subscriber station has stopped by for some obstacle and does not hear requests. And only if some predetermined interval is exceeded, the central station closes the channel that does not respond to subscriber station requests.

There is also a case of canceling the distribution at the initiative of the central station to provide a channel to a high-priority subscriber, for example, providing a high-speed channel to a commander or to transmit messages related to emergency situations. Under normal conditions, the allocation allocated to the subscriber station is not reduced or canceled at the initiative of the central station, i.e., the subscriber is guaranteed the allocation of a channel of the required quality.

The central station analyzes the received packets for errors and further transmits the corrupted packets, depending on the importance of the transmitted information. Since the transfer of information between subscriber stations occurs through the central station, when errors are detected in the incoming information packets, the central station performs the following actions:

If an error is detected in the packet of multimedia information (speech, video), moreover, in the information part of the packet, then such a packet is transmitted to the addressee. If the error is localized in the header of the multimedia information packet, then the packet is supplied with a new header and transmitted to the addressee. If an error is detected in a packet of information of the most importance (data), then the central station refuses to transmit such a packet to the addressee and such a packet can be retransmitted by decision of higher protocols, thereby eliminating the physical layer from retransmission procedures. As a result, not all corrupted packets are retransmitted, which provides additional savings in network bandwidth.

The central station of a given network can simultaneously operate as a subscriber station in a network of a higher hierarchy level, which, in turn, consists of many similar stations. To ensure reliable interaction with the central station of another network of the system, the central station transmits and receives information from the central station of another network in a separate frequency band, which differs from the radio frequency in this network, using another high-frequency path and another antenna. The time frame of the exchange between the central stations of neighboring networks, unlike the prototype method, is not tied to the temporary frame of the exchange between the central station and the corresponding subscriber stations.

Thus, in the described method for the allocation of time intervals in the radio communication network channels, an increase in the noise immunity of the establishment of connections is achieved by minimizing unregulated broadcasts by subscriber stations, as well as providing a channel of the required quality for a long period of time.

In the prototype method, in an unregulated request interval, subscriber stations transmit a rather long transmission request packet containing a number of fields with service data, including the subscriber station identifier. The longer the packet, the less likely it is to correctly receive this packet; therefore, higher probability of repeated requests and higher likelihood of transmission collisions. In addition, the time of the unregulated interval is spent on the transmission of service data. In the proposed method, the transmission request occurs in two stages: the registration procedure of the subscriber station and the survey of registered subscriber stations. The registration package, which is transmitted by the subscriber station for the first time on air, is reduced to a minimum: it contains only the subscriber station identifier, and all other service data is transmitted during the polling procedure in a specially allocated service interval, without interfering with other stations, i.e., transmission service messages necessary for establishing connections, taken out of the unregulated frame interval in adjustable, thereby increasing the likelihood of establishing connections.

Since the registration procedure is carried out regardless of whether the given subscriber station has packages for transmission, the authors used the term “registration” in the formula and description as opposed to the term “transfer request”, which is used in the description of the prototype patent and denotes a slightly different function .

Data on registered subscribers is used in protocol functions, and can also be useful to the network owner as information about the safety of network subscribers, if it is, for example, a special-purpose system or a system for collecting information from any unattended objects.

In addition, the proposed procedure for providing and maintaining a channel for transmitting information ensures long-term use by the subscriber of the channel of the requested quality regardless of the activity of the transmissions, if necessary, changing the channel without disconnecting the connection and closing the channel mainly at the subscriber’s initiative.

The interaction between the central stations of neighboring networks, unlike the prototype method, is not tied to the time frames of each network.

Therefore, the proposed method for the distribution of time intervals in network radio communication channels provides noise immunity and reliability of connections in a system of several networks due to the absence of collisions between transmissions of registered subscriber stations, as well as providing the subscriber with a guaranteed channel of the required quality for a long period of time.

Functional diagram of a device for implementing the proposed method is presented in figure 2, where the following notation is introduced:

1 - display and control unit;

2 - the first antenna;

3 - the first block of a power amplifier and a low noise amplifier;

4 - the first block receptor exciter;

5 - the first programmable logic unit;

6 - terminal block with terminal equipment;

7 - controller;

8 - processor unit;

9 - the second antenna;

10 - the second block of the power amplifier and low-noise amplifier;

11 - the second block receptor exciter;

12 is a second programmable logic unit.

The device with which the proposed method is implemented includes an interface unit 6 connected to a common bus, a processor unit 8, the first 5 and second 12 programmable logic units, as well as an indication and control unit 1, the first 2 and second 9 antennas, the first 3 and the second 10 blocks of the power amplifier and low-noise amplifier, the first 4 and second 11 blocks of the exciter and controller 7, the first group of inputs and outputs of which are connected to the second group of inputs and outputs of the processor unit 8, the third group of inputs and outputs in which it is connected to the group of inputs and outputs of the indication and control unit 1, the second and third groups of inputs and outputs of the controller 7 are connected respectively to the groups of inputs and outputs of the first 3 and second 10 blocks of the power amplifier and low-noise amplifier, the first single inputs and outputs of which are connected respectively with the first 2 and second 9 antennas, and the second single inputs and outputs of the power amplifier and low-noise amplifier blocks are connected respectively to the single inputs and outputs of the first 4 and second 11 exciter blocks, groups inputs-outputs of which are connected respectively to the second groups of outputs, the inputs of the first 5 and second 12 programmable logic blocks whose outputs are respectively connected to groups of the first and second inputs of the controller 7 groups.

The device with which the proposed method is implemented works as follows.

The display and control unit 1 comprises a keyboard for entering station control commands and a liquid crystal display for displaying control commands and station conditions. With the help of block 1, a station operating mode is selected (central or subscriber) and a number of other auxiliary functions.

The block of interfaces with terminal equipment 6 provides the connection of the device to standard interfaces, such as, for example, RS-232, RS-422, E1, telephone, etc., and provides simultaneous service to users connected to different joints.

The processor unit 8 provides parallel execution of user application protocols connected to the joints of the interface unit with terminal equipment 6, and converts the data coming from the interface unit with terminal equipment 6 into a data format for transmission, that is, it generates service and user information packets, as well as performs the inverse transformation of packets coming from the first 5 and second 12 programmable logic blocks into user application formats. In addition, the processor unit 8 provides the execution of a program containing modules of the protocols of interaction between subscribers of the data link network of the BOC model [1]: in the transmission mode, the processor unit 8 generates packets, fills them with service and user information, and issues these packets in blocks 5 and 12 In the receiving mode, the processor unit 8 extracts service and user information from the packets coming from blocks 5 and 12, converts them into the corresponding formats and sends them to the interface unit with terminal equipment 6. If this device works as a base station, some packets are sent back to blocks 5 and 12 for transmission to the corresponding subscriber stations.

If this device operates as a base station, then the processor unit 8 provides the functions of the network access protocol related to the registration of subscriber stations in the network, call management, resource allocation, etc.

If this device operates as a subscriber station, then packets with an identifier of the station with a random delay for registration in the network of this subscriber station are formed in the processor unit 8.

In addition, the processor unit controls the operation of the controller 7, which, in turn, controls the blocks of the power amplifier and low-noise amplifier 3 and 10. Control functions include: turning on the power amplifier, controlling the operation modes of the power amplifier and low-noise amplifier, etc. In addition, the controller 7 receives commands for switching the reception-transmission modes from the first and second programmable logic blocks 5 and 12.

The first programmable logic block 5, the first exciter block 4, the first block of the power amplifier and low-noise amplifier 3, and the first antenna 2 perform the functions of the physical and channel layers of the BOC model for radio exchange between stations of a given network [1]. In the transmission mode, the first programmable logic unit 5, upon a command from the processor unit 8, generates a synchronization signal, performs the specified arrangement in time intervals of packets coming from the processor unit 8, performs digital modulation and provides a signal to the first exciter unit 4, where the signal is transferred to the carrier frequency, then the signal enters the first block of the power amplifier and low-noise amplifier 3 and then to the first antenna 2. At the same time, the operation mode of block 3 (reception or transmission) is controlled Remove from the first programmable unit 5.

In reception mode, the signal from antenna 2 is amplified in the first block of the power amplifier and low-noise amplifier 3. In the first block of the exciter 4, the signal is transferred to the video frequency, and the analog video signal is output to the first programmable logic block 5. In block 5, the analog signal from the first block of the exciter 4 is converted into digital form, then synchronization, demodulation and separation of service and information packets that are issued for processing to the processor unit 8 is performed.

The second programmable logic block 12, the second exciter block 11, the second power amplifier and low-noise amplifier 10 and the second antenna 9 are connected in series similar to blocks 5, 4, 3 and 2. If this device works as a central station, then blocks 12, 11 , 10 and 9 are used for radio communication with the central station of another network, with the second antenna 9 being predominantly selected with a narrow radiation pattern, while the first antenna 2 usually has a circular pattern. If this device operates as a subscriber station, then blocks 12, 11, 10, and 9 are used for radio communication with its central station, and blocks 5, 4, 3, and 2 can be used to communicate, for example, with portable stations in the vicinity of this subscriber station station. Structurally, pairs of the same blocks 3 and 10.4 and 11, 5 and 12 can be identical. An example of the architecture of such a network is shown in FIG. 3, where the stations described above are conventionally depicted in the form of rectangles with two antennas (two transceiver paths). The number 2 indicates the antennas with a pie chart, and the number 9 - the antennas with a narrow radiation pattern. The central station ЦС1 carries out radio communication with subscriber stations of its network (AC1 ₁ -ACN ₁ ) through an antenna with a pie chart 2, and the subscriber stations AC1 ₁ -ACN ₁ work with their central station ЦС1 through directional antennas 9. In this case, the central station ЦС1 works with the central station DS2 through a directional antenna 9.

In addition, each of the subscriber stations AC1 ₁ -ACN ₁ can control several portable stations (Fig. 3 shows portable stations PS1 ₁₂ -PSM ₁₂ only around the subscriber station AC2 ₁ ).

From radio stations that implement the proposed method, you can create networks of various architectures. For example, figure 4 presents an embodiment of the use of this device for constructing microwave links. In this case, directional antennas 9 are mainly used. This use case of the proposed method allows constructing communication systems covering large territories.

The execution of blocks 5 and 12 in the form of programmable logic blocks allows you to change the types of digital modulation used to transmit and receive signals [5, 6, 7]. For example, you can use binary or quadrature phase shift keying, as in the prototype, as well as parallel composite signals based on Walsh functions (OCDM), orthogonal frequency multiplexing (OFDM), etc. [2, 3].

Thus, the device for implementing the proposed method for the distribution of time intervals in the radio communication network channels allows to fulfill all the requirements of the proposed method and provides noise immunity and reliability of the network connections due to the absence of transmission collisions of registered subscriber stations, as well as providing the subscriber with a guaranteed resource for a long period of time.

Information sources

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2. Prokis J. Digital Communications. Per. from English - M .: Radio and communications, 2000.

3. Andren S., Webster M. CCK Modulation Delivers 11 Mbps for High Rate IEEE 802.11 Extension. Harris Semiconductor, 2401 Palm Bay Road, N.E. MS: 62A-024 Palm Bay, Florida, WIRELESS SYMPOSIUM / PORTABLE BY DESIGN CONFERENCE SPRING, 1999.

4. Smith S.W. The Scientist and Engineer's Guide to Digital Signal Processing. - San Diego, California: California Technical Publishing, 1999.

5. Chassaing R. DSP Applications Using With and the TMS320C6x DSK. - New York, John Wiley & Sons, Inc., 2002.

6. “Xilinx ISE 6 Software Manuals”, www.xilinx.com, support.xilinx.com (Xilinx Product Software Manuals).

Claims (1)

A method for distributing time intervals in radio communication network channels, including assigning one of the network stations to a central station, on the central station side dividing the communication channel into time frames, transmitting a synchronization signal, dividing time frames into time intervals, where network stations are allowed to transmit and receive information, distribution subscriber stations of temporary sub-intervals (slots), where each subscriber station can transmit and receive information, exchange transmissions with a central station another network of this system in a frequency band different from the frequency band in which the subscriber stations of this network operate, and on the side of the subscriber station, establishing synchronization with the central station, receiving and highlighting service information on the allocation of time intervals for transmitting and receiving user information packets, receiving packets of user information in accordance with the distribution of time intervals and transmitting packets of user information in accordance with the distribution of time int intervals, characterized in that in the time frame of the central station after transmitting the synchronization signal, a time interval is allocated for transmitting service information packets from the central station to the subscriber stations, then a time interval divided into time slots is allocated for transmitting user information packets from the central station to the subscriber stations, then allocate a time interval for registration of subscriber stations, then allocate a time interval divided into time slots for receiving service and user information from subscriber stations in accordance with the slots allocated to them, while on the subscriber station side, synchronization with the central station is established, service information packets are received from the central station during the entire interval of transmission of service information and commands addressed to them for opening service channels are allocated ; on the side of the subscriber station, which is broadcasting for the first time, after establishing synchronization with the signal of the central station, during the registration interval a packet with the identifier is sent in the direction of the central station and waiting for commands to open the service channel from the central station; on the side of the central station, a packet with an identifier is received from the subscriber station during the registration interval and, in the interval for transmission of service information packets, in subsequent frames, commands are sent to open the service channel of the subscriber station, the identifier of which was successfully received; on the side of the subscriber station that has received commands to open the service channel, service information packets are transmitted in the time slots allocated to it; on the side of the subscriber station that transmitted the identifier but did not receive commands to open the service channel, the identifier is repeated in the registration interval of the next randomly selected frames; on the side of the central station, service polling packets are periodically transmitted in the direction of registered subscriber stations, opening service channels for transmitting responses to polling packets and, if necessary, distribution requests from registered subscriber stations; on the side of the central station transmit service information packets with commands to open channels for transmitting packets of user information from subscriber stations requesting distribution; on the side of the central station, packets of user information are received from subscriber stations in the time slots allocated to them for one or more frames; on the side of the central station, periodically optimize the use of time intervals in the frame, while the active subscriber station allocates a new distribution and continues to receive signals on the old distribution until communication is established on the new distribution, after which the channel is closed on the old distribution; on the side of the central station, close the channel for transmitting user information packets by the corresponding message from the subscriber station or in the absence of a response from the subscriber station to a given number of polls; on the side of the central station, they analyze erroneously received information packets according to the importance of messages and transmit to the addressee error-free and damaged packets with information of the lowest degree of importance and only error-free packets of information of the highest degree of importance; in addition, from the central station, radio is exchanged with the central station of another network that is part of the system, regardless of the time frames of its network.

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