Radio resource management in a radio telecommunication network

The present invention relates to mobile radio networks and, more particularly, to the management of radio resources to be assigned to terminals in such a network. 5

Mobile radio networks normally cover different geographical areas through different radio cells.

A terminal that is communicating in a radio communication network has radio resources assigned to it in a first cell of the network and on which it can transmit and / or receive data and / or voice. In the event that this terminal moves, it is possible that the radio resources already allocated in this first cell will not allow this terminal to continue the ongoing communication in a satisfactory manner. In this case, new radio resources may be assigned to it in a second cell to allow it to communicate again under appropriate conditions. Some networks guarantee a continuity of communication in case of cell change. Such is the case of networks of cellular architecture especially. In others, the previously established communication is interrupted and a new communication is established in the second cell, such is the case in some WiFi networks.

A management of radio resources of this type 25 comprises a decision-making stage of a change of radio resources from the first cell to the second cell.

In some telecommunications networks, such a cell change decision is made at the level of a centralized network entity that is responsible for managing a plurality of cells in the network. Such is the case in a telecommunications network based on a protocol of type UMTS (by “Universal Mobile Telecommunication System”) defined

by the 3GPP standardization body (for “3rd Generation Partnership Project Agreement”). These networks are based on a hierarchical cellular architecture in which a network entity, or base station, or also Node B, is responsible for one or more radio cells and a central controller, or 5 RNC (for “Radio Network Controller” ), is responsible for one or more entities of Node B. In such an architecture, the radio resources assigned to a terminal in a cell associated with a Node B, are managed by the central controller in charge of this Node B. 10

This central controller has, in particular, information related to the load of the cells it manages, as well as information related to the signals exchanged in those cells between the Node B entities and the terminals respectively. Based on this information, you are then able to make a cell change decision for a terminal located in one of the cells you manage. Thus, in case of mobility of a terminal that is communicating, a transfer decision between cells can be made by the central controller. The management of radio resources is in this case a centralized management and allows a decision to change cells based on centralized information related to the different cells managed by the central controller. 25

However, in other telecommunications networks, the management of radio resources in mobility is decentralized to the level of each cell. These networks are based on a distributed architecture, in which each cell is responsible for the cell change decisions made for its terminals.

Such is the case in WiFi-type networks, based on the IEEE 802.11 protocol (by “Institute of Electrical and

Electronics Engineer ”). Thus, when a mobile terminal detects that the radio resources that have been assigned to it in a cell managed by a first access point, are no longer adapted to its communication, it searches for a second access point that offers better conditions for it. communication. For example, the terminal determines a power level associated with a signal received from the first access point of the network that manages these communications. Then, when this power reaches a relatively weak level, the terminal determines levels of power associated with signals received from other access points in the network. You are then able to select the second access point for the management of your communications based on these different power levels. Thus, in such a context, the management of radio resources 15 is carried out in a decentralized manner at the cell level and more precisely in the example described above, at the level of each of the terminals in the cell.

In general, when the decision to change the cell is taken at the level of the cell, whether this decision is made at the level of the terminal itself or even at the level of the access point of the cell, it is not easy to base this decision on information relative to the radio resources in the potential target cell (s) of the cell change.

A document WO 2005084146 proposes to take into account information related to the radio resources of the neighboring cells in order to decide a transfer of cells for a network terminal. More precisely, 30 during such a transfer, it is provided that the base station used for the current communication of this terminal, that is the service base station,

request QoS service quality information (by “Quality Of Service”) from neighboring cell base stations. These neighboring base stations then respond to this service base station indicating the requested QoS information. Then, this QoS information is then transmitted to the terminal in question, the latter taking the final decision of the cell transfer.

However, this type of radio resource management has the disadvantage of generating a complementary signal traffic whose quantity is directly related to the amount of messages exchanged in relation to the QoS information between the service base station and the different base stations neighbors

In addition, the reliability of such a method is based on the robustness of the link between the base station of the current cell and the base stations of the potential target cells. Such a feature weakens the yields of this method under certain network conditions.

The present invention does not have the drawbacks mentioned above.

The invention allows, in particular, to reduce the amount of messages required to take into account, at the level of a cell, information on radio resources relative to other cells of a telecommunications network. 25

A first aspect of the present invention proposes a method of managing radio resources in a telecommunications network comprising a plurality of radio cells and a database that is associated with said plurality of cells and comprising information related to resources. radius of each radio cell of the plurality of cells, this database being managed by a database management entity. He

The procedure comprises the following stages at the level of a first cell:

/ a / issuing to the database management entity a message requesting information regarding radio resources of at least a second cell of said plurality of cells;

/ b / receive a response message from the database management entity indicating said requested information; and

/ c / decide to request radio resources in said second cell based on said information received.

A database is thus advantageously associated with a plurality of cells in a network, and allows a cell of this plurality of cells to be provided with information about neighboring cells so that a cell change decision can be made. relevant, at the level of said cell.

Thus, information regarding radio resources can easily be sent to a cell that requests them, when the latter wishes to determine if it is desirable that one of the terminals with which it communicates uses radio resources from another cell of the net. The information received from the database management entity in response to such a request can then be used as input for mobile decision algorithms, widely known to those skilled in the art, managed in the cell. It may eventually be provided to take into account, at the same time, at the input of the algorithm, other information, such as measurements made by the terminal (s) in different cells.

A cell change decision of a terminal is taken at the level of the cell, that is to say at the level of a

entity belonging to the cell. An entity of this type can be a radio resource management entity of the cell or even the terminal for which such a cell change decision must be made.

Indeed, in a first variant, it may be provided that the radio resource management entity of the cell in question is responsible for making the cell change decision for the terminals that are communicating with it. In this case, the radio resource management entity of the cell may issue a request message 10 destined for the database management entity. The latter responds by issuing a response message to the radio resource management entity in question, which, after having made a decision as to a possible cell change, report it to the terminal.

In a second variant, it may be provided that the responsibility for this decision-making, at the cell level, rests with the terminal affected by this decision. In the latter case, information relating to radio resources 20 may be requested by the radio resource management entity of the cell in question, received by the radio resource management entity, and then transmitted from this management entity. of radio resources to this terminal. 25

Alternatively, it may be provided that, in the event that the terminal is in charge of the cell change decision, it directly requests this information from the database management entity. Then, it receives directly from this database management entity 30 the requested information from which it can make a decision.

It is noted that the stages / a / a / c / can be set

in practice while radio resources have already been allocated to the terminal in the first cell. This case corresponds to a cell handover, or "handover."

The stages / a / a / c / can also be implemented while the terminal requests radio resources in the first cell. This case corresponds to a context of admission of a terminal in a network cell.

The present method can be advantageously applied to any type of service, and in particular to telecommunications services based on a transmission per packet, according to an IP protocol (by "Internet Protocol").

The telecommunications network can offer a set of data flow types to which respective levels of quality of service are associated. The information request message relating to radio resources may then indicate information relating to a list of cells comprised in the plurality of cells and at least one type of data flow of said set of data flow types. twenty

The response message may indicate, for each cell in the list of cells indicated in the corresponding request message and for the type of data flow indicated in the corresponding request message, a response based on a number of available radio resources 25 in said cell and at the level of quality of service associated with the type of flow indicated in the request message.

In such a context, a database comprises, for each cell of the telecommunications network 30 in question, and for each type of data flow offered in this network, information relating to the radio resources in the cell in question that allow to determine if this

cell can guarantee the QoS level associated with this type of data flow.

It may be provided that the information relating to a list of cells corresponds to an identifier of the cell that issues the request message and that the database management entity 5 determines the list of cells corresponding to the response message based on an association between an identifier of each cell and a list of cells, this association being stored in the database. In a variant, the information relating to a list of cells corresponds to a list of cell identifiers for which the request message has been issued. In this case, the database management entity is able to directly retrieve the requested information related to all the cells listed in the request message. In an embodiment of the present invention, the response message also indicates, for each cell in the cell list and for the type of data flow indicated in the corresponding request message, a number of users 20 to whom It can serve the cell for the type of data flow indicated. Such an indication can be pertinently taken into account in a cell change decision algorithm.

In one embodiment of the present invention, a cell periodically applies a planned radio resource allocation.

In such a context, the cell issues an update message from the database destined to the database management entity after each of said radio resource allocations. Then, upon receipt of this update message, the database management entity updates so

corresponding information stored in the database.

Thus, advantageously, the database is updated pertinently on a regular basis.

The response message can also indicate, for each cell in the cell list and for the type of data flow indicated in the corresponding request message, a level of reliability corresponding to the number of request messages that have been received from the last update of the database and that indicate 10 said cell.

Thus, even if there has not yet been an update of the database in relation to changes of cells from certain terminals towards a given cell, it is possible to take into account potential changes towards this cell. Indeed, the number of request messages received for this particular cell is taken into account here and it follows that it is possible that they affect modifications close to the radio resources of this cell, particularly in the case that at least some 20 of these Request messages will result in a cell change to this particular cell.

A second aspect of the present invention proposes a radio resource management entity adapted for the implementation of a method according to the first aspect of the present invention.

A third aspect of the present invention proposes a terminal adapted for the implementation of a method according to the first aspect of the present invention. 30

A fourth aspect of the present invention proposes a database management entity adapted for the implementation of a method according to the first

aspect of the present invention.

A fifth aspect of the present invention proposes a telecommunications system comprising a database management entity according to the fourth aspect of the present invention and one of the group comprising a terminal according to the third aspect of the present invention and an entity of radio resource management according to the second aspect of the present invention.

A sixth aspect of the present invention proposes a computer program intended to be installed in a database management entity 10 according to the fourth aspect of the present invention, comprising instructions suitable for practicing the method according to the first aspect of the present invention, during a program execution by means of processing means of the database management entity 15.

A seventh aspect of the present invention proposes a computer program intended to be installed in a terminal according to the third aspect of the present invention, which comprises instructions suitable for practicing the method according to the first aspect of the present invention, during an execution of the program by means of terminal processing means.

An eighth aspect of the present invention proposes a computer program intended to be installed in a radio resource management entity 25 according to the second aspect of the present invention, comprising suitable instructions for practicing the method according to the first aspect of the present invention, during program execution by means of processing means 30 of the radio resource management entity.

Other aspects, objectives and advantages of the invention will become apparent upon reading the description.

of one of its embodiments.

Also, the invention will be better understood by means of its drawings, in which:

- Figure 1 illustrates a telecommunications network architecture according to an embodiment of the present invention;

- Figure 2 illustrates an exchange of messages within a telecommunications network according to an embodiment of the present invention; and

- Figure 3 illustrates a basic update of 10 data according to an embodiment of the present invention.

Figure 1 illustrates a decentralized telecommunications network architecture according to an embodiment of the present invention. fifteen

A telecommunications network of this type comprises a plurality of cells 13-15 to which a database 12 is associated. This database can be managed by a database management entity 16 comprising:

- a first interface unit 17 with said plurality of cells 20 adapted to receive from these cells messages requesting information relating to radio resources of at least one other cell of this plurality of cells and adapted to issue a corresponding response message 22 to request message 21; and 25

- a second interface unit 18 with the database 12 adapted to retrieve the information related to the radio resources requested by a request message 21.

The first interface may receive a message 21 of 30 request for information relating to radio resources indicating information relating to a list of cells and at least one type of data flow.

The second interface can then retrieve a response in the database for each of the cells and for that type of data flow.

When the information relating to a cell list corresponds to an identifier of the cell that issued the request message, the database management entity determines the list of cells corresponding to the response message based on an association between an identifier. of each cell and a list of cells, this association being stored in the database. 10

The second interface can also retrieve in the database a number of users that can be served in said cell for the type of data flow indicated in the request message and in each of the cells in the indicated list. fifteen

The first interface can also receive update messages from the database respectively from the cells of the plurality of cells and the second interface unit can advantageously update the database based on information contained in these update messages. The first interface can then issue a response message 22 indicating, for the cells and the type of flow indicated in the request message, a level of reliability corresponding to the number of request messages that have been received since the last update of the the database and that indicate the cell in question.

Each radio cell comprises a radio resource management entity 19. A radio resource management entity of this type may correspond, for example, in the case of WiFi networks, to an access point.

In an embodiment of the present invention,

can understand:

- a broadcasting unit 101 adapted to issue a message 21 requesting information concerning radio resources to the database management entity 16; 5

- a reception unit 102 adapted to receive a reply message 22 from the database management entity 16 indicating the requested information; and

- a decision unit 103 adapted to decide to request radio resources in another cell based on the 10 information received.

Each of these cells 13-15 is responsible for making decisions regarding the management of radio resources, these decisions in particular corresponding to a management of the mobility of terminals that are already communicating in the cell, or even control of admission of a terminal communication in the cell in question.

These cells are therefore associated with the database 12 which is responsible for providing each of them with 20 information related to the radio resources of the other cells.

A user of a terminal 10, who wishes to transmit and / or receive data, requires radio resources in a cell of the network. The communication that the terminal wishes to effect corresponds to a data flow of a certain type of data flow offered in this network.

The terminal 10, in an embodiment of the present invention, comprises:

- a reception unit 104 adapted to receive a response message 22 from the radio resource management entity indicating information relating to the radio resources of a second cell, having

requested such information from the database management entity by the first cell; and

- a decision unit 105 adapted to decide to request radio resources in said second cell based on said information received. 5

The information requested from the database management entity 16 by the first cell may, in an embodiment of the present invention, be requested by the terminal by issuing a message 21 requesting information relating to radio resources of 10 At least the second cell.

A telecommunications network of this type offers a plurality of data flow types, such as an FTP data stream (by "File Transfer Protocol"), or HTTP type (by "HyperText Transfer Protocol"), or 15 including a voice over IP data flow, or voice over IP with silent compression, or also a video type data stream, etc. Standardization bodies define different types of data flow that correspond to different types of radio resource allocations. twenty

Thus, for example, in a UMTS-type network (by “Universal Mobile Telecommunication System”), a type of data flow that requires a certain maximum flow rate corresponds to a type of radio resource allocation (or “Radio Bearer ”), Which can be defined by a fixed number of WCDMA codes (by“ Wideband Code Division Multiple Access ”).

In a telecommunications network of the type IEEE 802.16e, different types of data flow are defined, for example, a type of real-time data flow 30 that has a fixed flow rate, or even a type of data flow in time real that presents a variable flow, or a type of data flow not in real time that presents a

variable flow, or also a type of “best effort” data flow, or a type of extended real-time data flow with a variable flow.

Generally, a service quality level (QoS) is associated with each type of data flow that is advantageously taken into account in a cell change decision according to an embodiment of the present invention .

To reach the level of QoS associated with a type of data flow, it is required that the radio resources 10 used during the transmission of this flow respond to certain limitations, such as a limitation relative to a latency time, a limitation relative to a fixed or guaranteed flow, a limitation of priority with respect to other types of data flow, etc. fifteen

Thus, an allocation of radio resources may take into account a level of QoS associated with the type of data flow that the terminal wishes to transmit and / or receive based advantageously on limitations of the type mentioned above. twenty

A cell change management of this type thus allows to guarantee a level of QoS corresponding to the communication desired by a terminal, in a radiotelecommunication network that manages mobility in a decentralized manner at the cell level. Advantageously, no 25 carries a significant additional signaling load, since a cell wishing to receive information that allows it to make a relevant cell change decision receives this information only from the database management entity, and not from the cells neighbors, 30 as in the prior art.

Figure 2 illustrates an exchange management between cell 14 and the base management entity 12 of

data during a request for information.

A message 21 for requesting information relating to radio resources from the cell 14 is sent to the database management entity 12.

This request message 21 may indicate the type of data flow desired by the terminal 10 for its communication, as well as information relating to a list of neighboring cells that are capable of receiving its communication.

A terminal may request radio resources for 10 different types of data flow simultaneously, each being associated with different respective quality levels. In fact, for example, a terminal can upload an FTP file while, on the other hand, it communicates by telephone. A request message can therefore indicate a plurality of types of data flow.

It may be provided that each cell knows a list of neighboring cells to which a user is capable of making a cell change. A list of this type can either be defined statically by an operator when establishing the network, or obtained dynamically. In the latter case, it may be an update of the list statically defined by the operator based, in particular, for example, on modifications made to the deployment of different radio resource management entities in the network. It is also possible that this list is generated or updated automatically thanks to statistical information related to the different cell transfers made from the cell in question. In this context, the information relating to a list of cells indicated in the request message 21 may correspond directly to a list of neighboring cell identifiers.

It may also be provided that the list of neighboring cells is directly associated with cell 14 in database 12. Under these conditions, it is no longer necessary to indicate this list in the request message. It is sufficient that the request message indicates the cell 14 in which the terminal is located, so that the database management entity is able to deduce from it a list of neighboring cells that can potentially accommodate the terminal 10. In this case, the information relating to the list of cells indicated in the request message 21 may simply correspond to an identifier of the cell 14.

The information request message 21 can also indicate a number of users, thus allowing a grouped request to be made on several users. fifteen

The issuance of this information request message 21 from the cell destined to the database management entity can be activated during an admission control of the terminal 10 in the cell 14. In fact, generally, when a terminal 10 asks to be admitted to the network, it issues a request for radio resources for a data stream of a certain type in cell 14, which it has selected according to any criteria such as, for example , a characteristic related to the received signal. If this cell 14 cannot provide this terminal with a level of QoS associated with this type of data flow, then a request 21 for information can be issued to the database management entity to allow admission of this terminal 10 in a neighboring cell that is able to provide you with the requested level of QoS.

When an admission of a terminal in the network is finally rejected for a type of data flow, the

The terminal can again issue a request for radio resources indicating another type of data flow associated with a lower level of QoS in order to, nevertheless, access the network. An embodiment of the present invention can still be easily applied here. 5

A request for information of this type can also be activated to manage the mobility of terminal 10 in cell 14. In this context, the terminal takes advantage of radio resources assigned to it in cell 14, but a loss is detected. of quality in relation to the data flow that is being transmitted. Cell 14 requests information from the database management entity to determine if a neighboring cell can offer a better quality for ongoing communication.

Such activation of the request for information from a database management entity 12 may be carried out by the terminal itself or even by a resource management entity of the cell in which the terminal is located.

Whatever the type of activation of the issuance of an information request message to the database management entity 12, upon receipt of this message, the database management entity retrieves the information relating to the radio resources of each of the cells in the list in question and related to the type of data flow indicated. It transmits 25 this information to the cell 14 through a reply message 22.

Then, the cell 14 processes the information received in this way so that it determines whether one of the neighboring cells is in a position to allocate to the terminal 30 10 radio resources that allow reaching the QoS level associated with the data flow considered, and this can be done processing either at the level of an entity of

radio resource management of cell 14, either at the level of the terminal 10 itself in question, or at the level of any other central entity of the cell.

The database 12 contains, for each cell k, where k is an integer between 1 and the number 5 N cell cells of the network, and for each type of data stream fi, i being an integer between 1 and the number of types of data flow offered in the Nflux network, information that allows you to provide a response to the request 21 issued from a cell. 10

The present invention encompasses any type of response that may be relevant to the cell that has requested information from the database management entity. This answer can be, for example, binary and consist of indicating whether "Yes" or "No" the neighbor cell 15 considered can meet the expectations of terminal 10. Thus, in the case where the number of available radio resources in the cell considered is sufficient for the type of data flow requested, this response indication corresponds to “Yes”, and in the case contrary to 20 “No” .

In one embodiment, an answer can be weighted. Thus, for example, the response can take into account not only the number of radio resources corresponding to the level of quality of service associated with the type of flow indicated in the request, but also the number of total or partial radio resources, for type of flow, which are available in the cell considered.

The answer may then correspond to a conditional response such as: 30

- "Yes, absolutely", in the particular case where the number of available radio resources in cell k is much higher than the number of radio resources

requested for the type of data flow fi.

- “Yes, except for sudden modification”, in the particular case where the number of radio resources available in the cell ka penalties is greater than the number of radio resources requested for the type of 5 data stream, in this In this case, it can be feared that, as a result of a rapid change in the allocation of radio resources in this cell k, there will be insufficient radio resources for terminal 10.

- "No, except for sudden modification", in the particular case in which the number of radio resources available in the cell ka penalties is less than the number of radio resources requested for the type of data stream fi; in this case it can be thought that, as a result of a rapid change of allocation of the 15 radio resources in this cell k, there are sufficient radio resources for terminal 10.

- "No, not at all", in the particular case where the number of available radio resources in cell k is much less than the number of radio resources 20 requested for the type of data stream fi.

In one embodiment of the present invention, the database 12 also contains for each cell k, for each fi flow, a corresponding number of users Nusuaries that can be serviced, being 25 users a whole number. The database 12 may also comprise a number of users for each of the possible responses, which represents the number of users that can be serviced in the cell with a value of the given response indication. 30

It may also contain additional information that allows the evaluation of a degree of reliability of the information in relation to the different types of information.

information contained in the database. Thus, a degree of reliability can be attributed in particular to each of the possible responses. This degree of reliability provides an estimate of the uncertainty about the information with which it is associated. The higher the value of this degree of reliability, the greater this uncertainty.

In an embodiment of the present invention, this degree of reliability can be based on a number of request messages 21 received by a cell k since 10 the last update of the database referred thereto. In this case, a response can be associated with this degree of reliability so that it is allowed to take into account the risk of changes in the allocation of radio resources in cell k depending on the number of messages of request for information received for this k cell since the last update.

It may also be provided that this degree of reliability is based on the information contained in these request messages so as to allow a more precise assessment of the risk of possible modifications that weighs on the response indicated in the response message issued from the entity of database management. Thus, advantageously, the number of radio resources that could potentially be requested can be taken into account if it is observed that all request messages correspond to an effective change to this cell k.

This degree of reliability, in an embodiment of the present invention, is expressed in the form of a reliability indicator, for each cell k, and each type of data stream fi. This is updated when requests are sent, by the other cells in the network associated with the

database 12, on the cell k and on the type of data flow fi.

Thus, this indicator can be reset to zero in each update of the database referred to cell k, and can be updated with the reception of every 5 request message received for cell k at the level of database 12 .

For example, it can be provided that, when a request refers to a number m of users, the reliability indicator of cell k for the type of data stream fi can be increased by m. Under these conditions, when a given cell makes a request for information about the cell k and the type of flow fi, it receives a response in the reply message, affected by the reliability indicator that has a value m. fifteen This given cell deduces from this that m terminals are capable of making a change from cell to cell k with the type of data flow fi, and therefore that there are radio resources capable of being assigned to these m terminals, that is to say that these radio resources may preferably be occupied, before they can be assigned to this given cell.

Therefore, the reliability indicator of cell k, for a type of data flow fi is a complementary information that allows a cell to base its decision of cell change on an assessment of the relevance of the other information contained in the reply message.

A reply message 22 may therefore comprise the following information for each cell in the cell list and for the type of data flow indicated in the reply message:

- an answer;

- a number of users; and

- an indicator value associated with this information.

Thus, upon receiving such a response message, cell 14 knows the conditional context in which the neighboring cells can provide the requested radio resources for terminal 10 and can consider this degree of reliability in a probabilistic manner, by example. Its value can be taken into account in a decision algorithm implemented in the cell. 10

The following table corresponds to an internal structure of the database 12 in an embodiment of the present invention. The database 12 contains information on a set of Nell cells, Nells being an integer. These cells can cover a more or less large geographic area.

In a variant, the information related to the radio resources of the different cells can be stored in several overlapping databases, in order to limit the size of each database. twenty

<dl><dt> Cell 1 </dt><dd> Flow f1 Response {Cell 1, Flow f1} Users {Cell 1, Flow f1} Reliability {Cell 1, Flow 1} </dd></dl>

<dl>&lt;dt /&gt;<dd> … </dd>&lt;dt /&gt;&lt;dd /&gt;&lt;dt /&gt;&lt;dd /&gt;&lt;dt /&gt;&lt;dd /&gt;</dl>

<dl>&lt;dt /&gt;<dd> Flow fN Response {Cell 1, Flow fN} Users {Cell 1, Flow fN} Reliability {Cell 1, Flow fN} </dd></dl>

<dl><dt> … </dt>&lt;dd /&gt;</dl>

<dl><dt> NELL CELL </dt><dd> Flow {N Cell, Flow f1} Response {N Cell, F fi} Users {N Cell, Flow f1} Reliability {N Cell, Flow f1} </dd></dl>

<dl>&lt;dt /&gt;<dd> … </dd>&lt;dt /&gt;&lt;dd /&gt;&lt;dt /&gt;&lt;dd /&gt;&lt;dt /&gt;&lt;dd /&gt;</dl>

<dl>&lt;dt /&gt;<dd> Flow Nflow {Cell Nell, Flow fN} Response {Cell Nell, Flow fN} Users {Cell Nell, Flow fN} Reliability {Cell Nell, Flow fN} </dd></dl>

Figure 3 illustrates an allocation of radio resources in cell 14 according to an embodiment of the present invention and the interaction of this allocation of

Radio resources with a database management.

At the level of each cell, a dynamic allocation of radio resources to users can be planned based on the number of users, their different types of data flow, their priorities, etc. 5

It is possible to provide a first planning level 31 corresponding to an adaptation of the allocation of resources in the cell. This level of planning may be associated with the management of users' QoS limitations, which may be limitations, temporary limitations or load limitations (for example, latency limitation, delay limitation between two different packets, etc.) . A planning level of this type is intended to ensure that the limitations associated with the different types of data flow are respected. fifteen

This level of planning can also correspond to an allocation of radio resources that does not guarantee a level of QoS, for a type of data flow. In this case, an adaptation can be made quickly, without limitation management relative to a QoS level of 20 users.

A second level of planning may correspond to an adaptation of the radio links depending on the rapid modifications of the radio channels. Such an adaptation may consist in particular of adapting a modulation and coding at the level of each frame, depending on the variations of the rapid fading, or in English "fast fading".

In an embodiment of the present invention, in the cell 14, periodically, a first level planning is carried out, according to a period T which can be of the order of 100 ms for example. This planning consists in determining, for each of the Nflux types of

data flow, radio resources Ri, 1, Ri, 2,…, Ri, n assigned globally to the Users, flow_i that ask to obtain the type of data flow flow_i, where n can depend on the number of users Users, flow_i as well as the characteristics of the type of data flow considered 5 flow_i. These radio resources may be time, code, time and code, time and frequency, frequency and code, or also time, frequency and code resources.

Then, once these radio resources have been allocated, a second level planning is performed in cell 14 to adapt the radio link based on rapid channel modifications. This link adaptation is limited by the number of resources allocated during second level planning. fifteen

In such a planning context, cell 14 issues an update message "UPD" of database 12 each time such planning is implemented. Being this periodic planning according to a period of time T, the database is periodically updated for the stored data in relation to the radio resources of this cell.

Thus, advantageously, the data stored in the database 12 can follow the variations associated with an admission of new users in a cell, either directly or as a consequence of a cell handover (or "handover"). Variations associated with a modification of the type of data flow of the terminal can thus follow, which may correspond to a modification of the type of flow that the terminal wishes to use, or also a modification of the type of data flow that has been decided by an internal planning in the cell. Such a modification associated with a schedule

it may be the result, for example, of a preferential occupation of certain radio resources of the cell by another user.

On the other hand, upon receiving each request message 21 received for a list of cells, the respective degrees of reliability associated with these cells are updated in database 12.

A database 12 according to an embodiment of the present invention offers a flexible and parametrizable structure so that it can provide information 10 related to the radio resources of the cells that are adapted to any type of decision algorithm known to the expert in the technique Thus, it can be provided that the structure of such a database, as well as its update, are advantageously adapted to the decision algorithm applied in the cell under consideration.

It may be provided that the different values ​​defined for a response to be indicated in a response message 22 can be interpreted at the cell level, the latter deciding, based on the threshold values ​​of the same, if the value It is acceptable for a given type of data flow.

In a variant, it may be provided that the database management entity translates a response value, stored as an absolute value, into values ​​adapted for the cells when it responds to requests from the latter. Such a variant can be advantageously implemented in the case where the cells 13-15 of the network are provided by different manufacturers and / or have 30 different respective processes.

The following sections describe the present invention in a network according to an IEEE type protocol

802.16e (WiMax network for example), in which the following five types of data flow are managed:

- “Unsolicited Grant Service” (UGS) that is adapted for real-time applications that generate fixed flow data, such as voice over IP without 5 silent compression.

- Extended Real-Time Variable Rate (ERT-VR) service that is adapted for real-time applications that generate variable flow data on a periodic basis, such as voice over IP with silent compression. 10

- “Real-Time Variable Rate” (RT-VR) service that is adapted for real-time applications with variable flow rates, which require a guaranteed flow and delay, such as a transmission of MPEG type video data. fifteen

- “Non-Real Time Variable Rate” (NRT-VR) service that is adapted for applications that require a guaranteed flow rate, but are not sensitive to delay, such as FTP (File Transfer Protocol).

- “Best Effort” (BE) service that is adapted for 20 applications that do not have a flow or delay limitation;

In such a context, a first level radio resource allocation planning can be carried out according to the following successive stages:

- allocate radio resources for all users requesting a type of UGS stream, between time-frequency intervals that are not assigned by default to other channels, such as pilot channels;

- allocate radio resources for all 30 users requesting an ERT-VR type of flow, between the remaining time-frequency intervals available; and

- allocate radio resources for all the

users requesting an RT-VR service, between the remaining time-frequency intervals available;

- allocate radio resources for all users requesting an NRT-VR service, between the remaining time-frequency intervals available; 5

- allocate radio resources for all users requesting a BE service, between the remaining time-frequency intervals available.

A planning of this type makes it possible to guarantee a certain QoS level associated with a certain type of data flow 10.

For example, if, at the end of a resource allocation planning, 14 enough time-frequency intervals remain in the cell, which respond to the required separation limitations, to provide an additional type of UGS flow to 15 two additional users, then the response indicated in the reply message for cell 14, and for the UGS flow, it may correspond to "Yes, except abrupt modification"; and the number of users Users can be equal to 2. 20

When a terminal 10 in cell 14, neighboring cell 13, sees the quality of its communication decrease, it can make measurements in neighboring cells, while cell 14 sends a message 21 to the database management entity 12 of request in relation to the 25 neighboring cells and for the type of UGS data flow.

In the case where, on the one hand, the measurements of terminal 10 allow to conclude that cell 13 is the one that is best suited for the request related to this terminal 10, and that, on the other hand, message 21 of 30 response indicate, for cell 13 and for the type of UGS data flow, a response corresponding to "Yes, except abrupt modification", a number of users Users

equal to 2, and a reliability indicator equal to 0, it can be deduced that the terminal can perform a mobility towards cell 14, while ensuring that the required level of QoS will be provided.

No limitation is imposed on a decision algorithm implemented in an embodiment of the present invention. Indeed, the processing of the information received from the database management entity 12 in the reply message 22 is described herein for illustrative purposes only. 10