FR2910753A1 - Shared medium access control channel access management method for telecommunication network, involves allocating access priority to priority customer station, and transmitting priority parameter to station by access point - Google Patents

Abstract

The method involves allocating an access priority to a priority customer station e.g. mobile terminal, where the priority is independent of traffic type. A parameter of the priority is transmitted to the station by an access point of a telecommunication IEEE 802.11 network, where the parameter of the priority defines priority access of a shared channel. A request for the associated priority transmitted by the station is received by a receiving module of the access point. The priority access of the channel is distributed to the station. An independent claim is also included for a method for accessing a shared channel in a telecommunication network.

Description

Methods for managing access to a shared channel in a network of

  wireless telecommunications. 1. Field of the invention

  The present invention relates to the field of wireless telecommunications and more specifically access to the channel (or MAC of English Medium Access Control or access control medium). 2. Technological background.

  The IEEE 802.11e standard improves the quality of service in the MAC layer. In particular, it specifies a coordination function called the hybrid coordination function (HCF). The HCF uses a contention-based access method called Enhanced Controlled Channel Access (EDCA). The EDCA method provides differentiated and distributed access to the wireless medium that includes four access categories. It allows support to deliver traffic with eight different user priorities. Thus, priorities are set in ascending order for the background, the best effort, the video and the voice. A set of parameters is allocated to each category of EDCA. An access point (or Access Point Access Point) of the IEEE 802.11 network transmits the parameters to be used by all stations in a management frame. When these parameters have not been specified in the access point, the station concerned uses default settings. The standard allows APs to use a different set of EDCA parameters than the one sent to stations. Thus, it may have a higher access priority.

  In summary, the IEEE 802.11 standard allows channel access for priority-based client stations based on the type of traffic. This priority management has the disadvantage of not being well adapted to certain uses, notably to the transmission of videos. by some stations. 3. Summary of the invention.

The object of the invention is to overcome these disadvantages of the prior art. More particularly, the invention aims to allow access to the channel by at least one wireless station to or from relay stations, with a better quality of service. For this purpose, the invention proposes a method of managing access to a shared channel in a wireless telecommunications network that includes at least one access point and a plurality of client stations. The method includes a step of assigning a priority to at least one priority client station. Advantageously, the priority is independent of the type of traffic. According to one particular characteristic, the method comprises a step of transmitting at least one priority parameter by an access point to at least one client station, the priority parameter (s) defining the priority of access to the shared channel by the customer station (s). According to an advantageous characteristic, the method comprises a step of identifying at least one priority client station. Specifically, the method includes a step of receiving an associated priority request, the request being transmitted by a client station. According to one particular characteristic, the method comprises a step of assigning a channel access priority as a function of the type of traffic to each of the non-priority client stations of the plurality of client stations. In this case, the priority of a priority client station is advantageously strictly greater than said channel access priority to the channel as a function of the type of traffic. According to a particular characteristic, the network is of the IEEE 802.11 type.

The invention also relates to a method of accessing a shared channel in a wireless telecommunication network which comprises at least one access point and a plurality of client stations. In order to optimize the quality of service, the method implemented by at least one priority station comprises a step of accessing the channel as a function of a priority assigned to said priority client station.

Advantageously, it comprises a step of receiving information representative of a priority of access to the channel, transmitted to at least one client station. According to another characteristic, it comprises a step 5 of assigning a channel access priority. 4. List of figures. The invention will be better understood, and other features and advantages will appear on reading the description which follows, the description referring to the appended drawings in which: FIG. 1 illustrates an example of a communication network architecture with elements implementing the invention; Figures 2 and 3 show schematically respectively an access point and a mobile wireless station belonging to the network 15 of Figure 1, according to a particular embodiment of the invention; Figures 4 and 5 show a priority management method implemented respectively in the access point of Figure 2 and in the station of Figure 3; and FIG. 6 illustrates an example of communication between different elements of the network of FIG. 1. Detailed description of the invention. FIG. 1 represents a wireless communication network 1, for example a local network of the IEEE 802.11 type. The network 1 comprises one or more wireless stations, fixed or, advantageously mobile, and for example two terminal stations (or MT of the English Mobile Terminal) or mobile (or MS of the English Mobile Station) or stations ( or SS of the English Subscriber 30 Station) 10 and 11. It also includes an AP access point 10 allowing communications without or from stations 10 and 11 and possibly an interface to one or more other wired networks or no. FIG. 2 schematically illustrates an access point 2 of the network 1 corresponding to the access point 10. The access point 2 comprises, interconnected by a bus 24 of addresses and data, also carrying a signal d clock: 2910753 4 - a microprocessor 21 (or CPU); a non-volatile ROM type memory (of the English Read Only Memory) 22; a random access memory or Random access memory (RAM) 23; a module 25 for transmitting a signal on the wireless link; and a module 26 for receiving a signal on the wireless link. Moreover, each of the elements 21 to 26 is well known to those skilled in the art. These common elements are not described here. It will be observed that the word register used in the description of the memories designates in each of the memories mentioned, as well a memory area of small capacity (a few binary data) that a memory area of large capacity (for storing an entire program or all or part of the representative data of a received audio / video service). The ROM 22 includes in particular a prog program 220. The algorithms implementing the steps of the method peculiar to the invention and described below are stored in the ROM 22 associated with the access point 2 implementing these steps. At power up, the microprocessor 21 loads and executes the instructions of these algorithms. The RAM 23 comprises in particular: in a register 230, the operating program of the microprocessor 21 charged at powering up the access point 2; client identifications (e.g., stations 11 and 12) in a register 231; the priorities associated with each client in a register 232; And - one or more messages including data or Packet Data Unit (PDU) associated in a register 233. Figure 3 schematically illustrates a client station 3 of the corresponding network 1, for example at one of the stations 11 or 12. The client station 3 comprises, interconnected by a bus 34 of addresses and data, also carrying a clock signal: a microprocessor 31 (or CPU); a non-volatile ROM type memory (of the English Read Only Memory) 32; a random access memory or RAM (Random Access Memory 5) 33; a module 35 for transmitting a signal on the wireless link; and a module 36 for receiving a signal on the wireless link. Moreover, each of the elements 31 to 36 is well known to those skilled in the art. These common elements are not described here. The ROM 32 includes in particular a program prog 320. The algorithms implementing the steps of the method specific to the invention and described below are stored in the ROM 32 associated with the station 3 implementing these steps. On power up, the microprocessor 31 loads and executes the instructions of these algorithms. RAM 33 includes: in a register 330, the operating program of the microprocessor 31 charged to power station 3; its identification as a client in a register 331 (which corresponds to the value associated with it in the register 231 of the access point); - his priority in a register 332; and one or more messages including associated data or PDUs in a register 333. According to some embodiments of the invention, the party associated with the channel access management in the access point 2 or the station client 3 is an electronic block comprising one or more discrete components (for example of the ASIC type or programmable components) or inserted wholly or partly in a component comprising other functions (for example ASIC comprising the memories 22 and / or 23 ( respectively 32 and / or 33) and / or the CPU 21 (respectively 31) for the access point 2 (respectively the client station 3)). According to other embodiments of the invention, the portion associated with channel access management is implemented wholly or partly in computer form (for example, by a signal processing processor).

FIG. 4 shows a priority management method implemented in the access point 2. During an initialization step 40, the access point 2 (and more precisely the microprocessor 21) initializes its different components and 5 variables. During this step, it can identify each of the client stations (for example with their MAC and IP addresses) and assign them a default access priority (for example a low priority or a priority by type of traffic). The identification can be static (an access point is configured by default to work with predefined client stations) or dynamic after a discovery procedure (via, for example, a UPnP (Universal Plug and Play) function. or universal branching and game in French.) Then, the access point allocates a priority to at least one priority client station During a step 41, at least one client station is identified as a priority client The CPU 21 then updates a strong priority associated with this client (or these client stations) in the register 231. The identification of a priority client can be done according to any method, such as, for example: receiving a specific message from this priority client, this message indicating that the client station itself is requesting a strong access priority; a priority client station identification ction of its type (communicated for example during the accession to the network (for example via a discovery message according to a UPnP protocol, or via the MAC address comprising a range of addresses or a field specific to a type of station )), a server-type client station being advantageously more important than a terminal-type client station (for example Set Top Box); and / or an interface with a user of the access point 2. Advantageously, the priority assigned to a priority client station is higher than the default priorities, in particular to the priorities defined according to the type of traffic. The priority of the access point is, according to different variants, greater than the priority assigned to a priority client station or less than this priority. According to a variant of the invention, several priority levels are defined for the stations identified as a priority. Thus, priority 2910753 7 can be made according to the characteristics of the priority stations, for example a telephone dedicated to emergencies will have a higher priority than other phones and a fortiori to those of client stations of another type. According to one variant, priority levels are differentiated according to arbitrary parameters: for example, for users of a paying access point (hot spot English), the access point assigns a priority to the client stations in question. subscription cost function. Then, in a step 42, the access point 2 constructs and transmits a message indicating a channel access priority to the client station identified as a priority. This message includes the MAC address of the client station and the priority assigned to it. According to a variant, if the client station has sent a request, a message comprising a simple answer of the accepted request type can be transmitted to the client station. In general, the message indicating channel access priority may be of different type. For example, based on the IEEE802.11 e standard (as defined in IEEE 802.11e-2005), it can be of the association response (or association response), re-association response (or reassociation response) or a response indicating a priority station (and possibly a priority level) being inserted in this message. According to the invention, the message can be defined specifically. The message can be transmitted at any time, and in particular, outside association or reassociation procedures.

FIG. 5 shows a priority management method implemented in the client station 3. During an initialization step 50, the client station 3 (and more precisely the microprocessor 31) initializes its various components and variables. During this step, it can identify itself and indicate its presence near the access point 3. Then, during a step 51, the station 3 grants itself a priority of access by default and the stored in the register 332. It can be a fixed low priority or a priority that is a function of the type or types of traffic transmitted by the station 3.

Then, during a step 52, the station 3 constructs and transmits a request to obtain a high priority at the access point (s) on which it depends. According to an alternative embodiment, and according to the way in which the access priorities to the channel are allocated by the access point or points, step 52 is omitted. Then, during a step 53, the client station 3 receives a message from an access point indicating a specific access priority.

During a step 54, the client station updates the register 332 according to the priority indicated in the message received in step 53. If the client station subsequently receives a diffused message assigning priorities according to EDCA, this message is not taken into account by the priority client station (except an explicit message asking the priority client station 10 or a set of priority stations to modify its priority parameters). Then, when a message is to be transmitted to an access point, during a step 55, the client station 3 accesses the channel according to a contention mechanism taking into account the priority that has been assigned to it. Step 55 is repeated each time a message is to be transmitted. Thus, step 55 is a step of accessing the channel according to a priority assigned to the priority client station 3. Step 52 can also be reiterated at any time (for example, depending on a parameter set updated by a network element, a user or an application). The client station 3 is listening to the data transmitted by the access point or points associated with it. Also, step 53 can also be repeated at any time. Figure 6 illustrates an example of communication between the access point 10 and two client stations 11 and 12 (these elements are represented by vertical lines, successive actions, events and / or transmissions are illustrated chronologically). After the transmission of a priority request 60 associated with the client station 11 to the access point 10, the latter responds to the client station 11 by a frame 61 comprising the priority assigned to this station. According to an alternative embodiment, the request 60 is omitted and a specific event allows the transmission of the frame 61. After decoding the received frame 61, the station 11 updates the register 332 during the step 54 illustrated above. .

Then, by way of illustration, the stations 11 and 12 respectively construct messages msg1 and msg2 during steps 62 and 63, respectively.

Subsequently, the stations 11 and 12 try to transmit these messages to the access point 10. They therefore enter a contention period 64 to access the channel. It is assumed that the priority (priol) of access to the channel of the station 11 is strictly greater than that (prio2) of the station 2 (for example priority by default or priority assigned by the access point). Also, the station 11 has a greater probability of being able to access the channel than the station 12 during the contention 14. It is assumed by way of illustration that the station 11 actually accesses the channel at the end of the contention 14 and transmits a message 65 (corresponding to msg1) at point 10 of access 10. At the end of a new contention 66 during which only station 12 tries to access the channel, the latter in turn transmits a message 67 (corresponding to msg2). Of course, the invention is not limited to the embodiments described above.

In particular, the architecture of the access points and the client stations may be different from those illustrated in FIGS. 2 and 3 respectively, in the respective function and / or the shape of the elements (the functions of the electronic elements may in particular be grouped together in a limited number of components or, on the contrary, split into several components) and their arrangement. In addition, the invention is not limited to wireless transmissions on networks of the IEEE 802.11 type but concerns all local wireless networks (that is to say covering a few meters) or covering a wide area (up to several kilometers (for example on IEEE802.16 networks). The invention is advantageously implemented in networks transporting video, in particular when the client stations transmit video sequences to different terminals. The invention can also be applied to other applications (for example, to the transmission of any data (computer data, audio data, voice, etc.). A high priority is advantageously attributed to a server. It can also be assigned to other types of client stations (for example, audio and / or video source (camera, microphone, telephone, etc.), computer data sources (sensors, calculators, etc.).

The invention applies equally well to a network comprising a single access point as to a network comprising two access points or a larger quantity (for example, 3, 4, 10, 10, etc.). .). According to the invention, only one level of high priority can be assigned. According to variants, several priority levels can be assigned; thus, client stations can have different levels of priorities. In addition, for the same level of priority assigned to a set of client stations, sub-levels can be assigned according to different criteria (for example, type of traffic, type of terminal, desired rate, etc.). According to a variant of the invention, a priority client station itself assigns an access priority to the channel, advantageously regardless of the type of traffic. In this case, according to different implementations, it can inform or not the access point.

Claims (11)

  A method of managing access to a shared channel in a wireless telecommunications network (1) which comprises at least one access point and a plurality of client stations, characterized in that it comprises an allocation step (41) a priority to at least one priority client station.   2. Method according to claim 1, characterized in that the priority is independent of the type of traffic.   3. Method according to any one of claims 1 and 2, characterized in that it comprises a step of transmitting (42) at least one priority parameter by an access point to at least one client station, the or the priority parameters defining the access priority to the channel shared by the at least one client station.   4. Method according to any one of claims 1 and 3, characterized in that it comprises a step of identification (41) of at least one priority client station.   5. Method according to any one of claims 1 to 4, characterized in that it comprises a step of receiving an associated priority request, the request being transmitted by a client station. 25   6. Method according to any one of claims 1 to 5, characterized in that it comprises a step of assigning a channel access priority according to the type of traffic to each of the non-priority customer stations of said plurality. 30   7. The method of claim 6, characterized the priority of a priority client station is strictly greater than said channel access priority to the channel depending on the type of traffic.   8. Method according to any one of claims 1 to 7, characterized in that said network is of the IEEE 802.11 type. 2910753 12   9. A method of access to a shared channel in a wireless telecommunication network which comprises at least one access point and a plurality of client stations, characterized in that the method is implemented by at least one priority station, it comprises a step of accessing the channel (55) according to a priority assigned to said priority client station.   10. Access method according to claim 9, characterized in that it comprises a step of receiving (53) information representative of a channel access priority, transmitted to at least one client station.   11. Access method according to claim 9, characterized in that it comprises a step of assigning a channel access priority. 15