PT1325651E - Channel allocation for communication system - Google Patents

Description

DESCRIPTION " ALLOCATION OF CHANNELS FOR COMMUNICATION SYSTEM "

FIELD OF THE INVENTION The present invention relates to the allocation of channels to users in a communication system, and particularly, but not exclusively, to the allocation of channels in a mobile communication system.

BACKGROUND OF THE INVENTION

In a typical cellular wireless network, the area covered by the network is divided into several cells. Each cell is served by a transmit / receive base station which transmits signals to and receives signals from terminals located in the respective cell associated with a particular transmit / receive base station. The terminals can be mobile stations, which can move between cells. Channel allocation involves allocating a channel to a particular connection. There is generally an uplink channel from the mobile station to the base station and a downlink channel from the base station to the mobile station. Channels can be defined by different frequencies, time slots and / or spreading codes. Allocating channels for some types of calls, such as data calls, also requires selecting the allocation period. In WCDMA 1, the allocation period is the period in the radio network controller in which the packet scheduler can change bit rates for packet users. Allocation of channels is done in a distributed way in the current networks. In particular, it is the responsibility of the controller of a base station to control the resources of its own base stations. In the GSM (Global System for Mobile Communications) standard, a base station controller (BSC) is configured to control channel allocation for a set of base stations.

In the proposed third-generation system using CDMA (Code Division Multiple Access), a radio network controller (RNC) is configured to control the allocation of channels to its own base stations. In the CDMA system, the base station is sometimes referred to as Node B. However, in this document, the term base station will be used. The controllers in the GSM and CDMA systems are configured to control multiple base stations. However, the number of base stations that are controlled is relatively small.

Accordingly, with this approach, the efficiency of any channel allocation is limited insofar as channel allocation coordination is only possible within the limited area of the controller itself. This means that you can not coordinate channel allocation between cells that are controlled by different controllers. This in turn means that the implementation of features that are intended to limit inter-channel interference in adjacent or nearby cells can not be achieved since the cells can be controlled by different controllers.

The problems described above will become more relevant in the future. In some of the newly designed network architectures 2, such as IP-based radio access networks, channel allocation functions are transferred from the controllers, such as the radio network controller and the base station controller, to the base station itself. This allows the implementation of a more efficient real-time (RT) channel allocation. However, this also eliminates the possibility of coordinating the allocation of channels by base stations controlled by the same controller.

The limitations of the boundaries of radio controllers are also particularly relevant when a network operator has more than one radio access system (eg a CDMA system and a GSM system) with a common coverage area. This is because it is not possible to coordinate channel allocation across different systems to reduce interference. In addition to third generation systems, such as CDMA, other systems are being developed, such as Wireless LAN (local area network), IS-41 (a U.S.A. version of CDMA), etc.

In the paper by Rozenstrauch A et al. : " 2 Phase RF Channel

Allocation ", March 1, 1995, Motorola Technical

Developments, Motorola Inc., Schaumberg, IL, US, Vol. 24, pages 70-71, discloses a method for switching a wireless communication channel between base stations of first and second systems in an overlapping area coverage of base stations. If the first system is unable to allocate a channel to satisfy a service request of a mobile subscriber, it issues a service request to the second system. If the second system has the resources, it responds positively to the request and the mobile subscriber terminates service 3 with a second system even if the initial service request was made with the first system. EP0496061 discloses a method for decentralizing the management of network traffic in a circuit-switched cable network. The channel control in the network is divided among several elements in a subdivided network (subnet). In order to maximize network capacity, traffic processing information is passed between the controllers of each subnet.

SUMMARY OF THE INVENTION

Embodiments of the present invention aim to solve one or more of the above-mentioned problems. The invention provides a solution according to the independent claims.

According to a first aspect of the present invention there is provided a cellular wireless communication system covering an area, said system comprising a plurality of first means, each of said first means being configured to control the allocation of wireless channels for at least one mobile station in a part of said area, said at least one of said first means configured to send wireless channel allocation information in the part of the area associated with said at least one first means for at least one of said first means, said at least one other of said first means being configured to consider said information received when controlling the allocation of wireless channels in the part of the area associated with said at least one of said first means. least one, another first medium. 0, at least one, first means one may be configured to send channel allocation information to said at least one other first means which is associated with a portion of said area adjacent to or at least partially overlapping to the portion of the area associated with said at least one, first medium. 0, at least one, first means may be configured to send power control information to said at least one other first means which is associated with a portion of said area adjacent to or at least partially overlapping the part of the area associated with said at least one, first means. Said at least one, first means may have routing information indicating that one or more other first means should be sent to the channel allocation information. Said channel allocation information may comprise cell information and / or channel allocation information. The cell information may include LAC and Cl (information to identify the cell). The channel allocation information may include the state of time slots (inactive / reserved / half of the total throughput or flow), base station DL power control used, MAY = frequency allocation index offset to the used mobile] . Said at least one first means may be configured to continuously send said channel allocation information to said at least one other first means. Said at least one first means may be configured to send channel allocation information when there is a change in said channel allocation information to the at least one other first medium. Said at least one first means may be configured to send said channel allocation information in response to a request of one of said at least one other first means. Said at least one first means may be provided with information identifying the at least one other first medium to which said information is to be sent.

A coordination means may be provided which receives said channel allocation information from said at least one first means. Said coordination means may be configured to route said channel allocation information to said at least one other first means. Said coordination means may be provided with routing information defining to which at least one other first means the channel allocation information from said at least one first medium is to be routed. Said coordination means may be configured to make channel allocation decisions for the at least one other first means by considering the channel allocation information from said at least one first means. Said coordination means may be provided on a network element separate from the other means.

At least one of the following methods may be used by said first means to allocate a channel: dynamic frequency allocation; dynamic channel allocation; and coordination of the use of high data rates.

A plurality of radio access networks may be provided, at least one of said first means being associated with one of said radio access networks and at least one of said first means associated with another of said radio access networks. access.

Aspects of the present invention provide a first means for channel allocation control as defined in Claims 1 and 12.

Aspects of the present invention provide respective methods for controlling the allocation of wireless channels in respective first means, the methods defined in Claims 31 and 32.

In another aspect, the present invention provides a coordination means for receiving wireless channel allocation information from at least a first means in a wireless cellular communication system, the coordination means being defined in Claim 33.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention and how it may be implemented, reference will now be made, by way of example only, to the accompanying drawings, in which: Figure 1 shows a first embodiment of the present invention with a single radio access network; Figure 2 shows the interconnections between base station controllers in the embodiment of Figure 1; Figure 3 shows a modification of the embodiment of Figure 1; Figure 4 shows a second embodiment of the present invention with two radio access networks; Figure 5 shows a third embodiment of the present invention with a radio access network where channel allocation is controlled by a base station;

Figures 6 (a) to 6 (g) illustrate communication at an exemplary interface; and Figure 7 (a) to (d) shows a method of communication between a source and a destination. 8

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE PRESENT INVENTION

Referring first to Figure 1, this shows a first embodiment of the present invention in which only a single radio access network 2 is present. In the embodiment shown in Figure 1, the network 2 is a GSM network. However, it should be understood that in alternative embodiments of the present invention the network may conform to any other standard and use any radio access technique. The area covered by the network 2 is divided into cells 4. In the embodiment shown in Figure 1, five cells are shown. This number is by way of example only and in practice a network will have many more cells. Each cell has an associated base station 6. Each base station 6 is configured to communicate with the mobile stations 8 in the cell 4 associated with the respective base station 6. Depending on the standard used, a mobile station may be in communication with more than one base station at the same time. Alternatively or in addition, a mobile station may communicate with a base station associated with a cell different from that in which the mobile station is located. This can occur if a mobile station is near a cell boundary zone.

Each base station 6 is controlled by a respective base station controller 10. In the embodiment shown in Figure 1, a base station controller 10 is configured to control three base stations while the other base station controller 10 is configured to control two base stations. This configuration is by way of example only and a base station controller may control only one base station or more than three base stations. The 9 base station controllers 10 are configured to control the channel allocation. The two base station controllers 10 are connected to each other. This allows each base station controller to transmit information about the channel state or cell state in the cells controlled by that base station controller to the other base station controller. This is described in more detail below.

In a preferred embodiment of the invention, the base station controllers transmit channel and / or cell status information to the other base station controllers controlling an area adjacent to that controlled by the transmitting base station.

Referring to Figure 2, this shows five base station controllers 10. As can be seen, the first base station controller 10a is connected to the second base station controller 10b and the third base station controller 10c. The second base station controller 10b is also connected to the third, fourth and fifth base station controllers 10c, 10d, and 10e. The third base station controller 10c is also connected to the fifth base station controller 10e. The fourth base station controller 10D is also connected to the fifth base station controller 10O. As you can see, each base station controller is not connected to each of the other base station controllers. In contrast, each base station controller is only connected to the base station controllers that control an area adjacent to the area covered by the base station controller in question. Thus, each base station controller only reports status information to the base station controllers that control an area adjacent to the area covered by the base station controller in question. . The adjacent area may be an immediately adjacent area or may be an area that is not immediately adjacent, but close enough to cause interference. The base station controllers to which a specific base station controller is connected may depend on the channel allocation method used, can be determined by the required channel allocation speed, by the required reduction in terms of interference and / or by any other parameter appropriate.

In a preferred embodiment, the base station controllers are not connected one by one as shown in Figure 2, but instead, all the base station controllers may be connected to a local area network.

Thus, in preferred embodiments of the present invention, each network element with a channel allocation entity sends channel state information to one or more neighbor channel allocation entities, which is an entity that is responsible for allocating channels in adjacent cells. In the context of the embodiment of Figure 1, the channel allocation entities are the base station controllers. Sending information may be implemented by defining in each of the channel allocation entities the identity of the or each neighboring channel allocation entity that requires information from the particular channel allocation entity.

A specific channel allocation entity will thus continually send information about the cell state and / or channel status to the identified channel allocation entity (s) which is responsible for allocating channels in 11 adjacent cells. Instead of continuously sending information, sending information can be done whenever there is a change in the cell state and / or channel state or in response to a request from a specific channel allocation entity.

When a channel allocation entity is making a channel allocation decision, the entity shall consider the information that the entity has, for example, from the base stations that are controlled in that way and the information received from the or each allocation of adjacent channels. The channel allocation entity may use any appropriate criteria in order to make a decision related to channel allocation. For example, the dynamic allocation of GSM channel frequency or a similar method can be used. Another example of a possible method that could be used is the dynamic allocation of TDD channels (time division duplexing) or a similar method. Yet another example of a possible method is the co-ordination of the use of high data throughput in CDMA or similar method. Another example is the Dynamic Frequency Allocation and Channels (DFCA) method. The exact information that is sent will depend on the method that is used to allocate channels and / or the type of radio access network. For example, in the case of a dynamic frequency allocation and EDGE channels, a channel allocation matrix can be sent. Other types of information could be sent by multicast. For example, power control information of the interfering base stations or uplink and downlink background noise interference matrix information could be sent by multicast. Multicast is when the same message is sent to multiple base stations. 12

The channel allocation entities are provided with an appropriate interface that enables the entities to be connected to each other. Alternatively, the cell state and / or channel allocation information may be added to the existing interfaces, such as the Iur interface to UTRAN (UMTS terrestrial radio access network). The protocol conveying this information is preferably flexible and retrocompatible.

Referring now to Figure 3, this shows a modification of the Figure 1 embodiment. In this embodiment, each base station controller 10 is connected to a network coordination element 12. A single network coordination element may be provided for the entire network or a plurality of network coordination elements may be provided for the network. In the latter case, some of the base station controllers may be connected to more than one of the network coordination elements. This is to ensure that, for a specific base station controller, a specific element of the coordination elements has information on all adjacent cells that needs to be considered when making a channel allocation decision.

If a coordination element is provided, the coordination element will make channel allocation decisions. In order to allow the coordination element to make the right decision, it will have information identifying the channel allocation entities for which the information should be considered when making a decision for a particular cell. In a modification thereto, the coordination element does not itself make the decision, but instead forwards the information it receives from the various channel allocation entities to the channel allocation entities that require that information. The coordinating entity would again have information so that channel allocation entities should be forwarded information from a specific channel allocation entity.

Referring to Figure 4, this shows a second embodiment of the present invention, wherein the system 14 comprises a first radio access network 16 and a second radio access network 18. The second network is shown, for clarity, in dashed lines. The first radio access network 16 is a GSM network, but could be any other type of radio access network. The second radio access network 18 is a CDMA network but, again, could be any other type of network. In some embodiments of the present invention, more than two radio access networks may be provided. Radio access networks may use the same standard or different standards.

The first and second networks 16 and 18 are shown in Figure 4 in overlap. It will be understood that, in alternate embodiments of the present invention, the nets may only partially overlap or may be provided side by side. The first network 18 is the same as the network shown in Figure 1. Accordingly, like parts are indicated by like references and will not be described in detail. The second network 18 has its network coverage divided into several 4 'cells, such as the first network 16. Each cell is provided with its own base station 6' which is configured to communicate with mobile stations in the cell associated with that cell and / or mobile stations located in an adjacent cell. Each base station 6 'is connected to a radio network controller 20. A radio network controller 20 is connected to two base stations while the other is connected to three base stations. In practice, a radio network controller 20 may also be connected to only one base station or to more than three base stations.

The radio network controllers 20 are connected to each other and to each of the base station controllers 10 of the first network 16. In preferred embodiments of the present invention, each controller, which is a base station controller 10 or a controller 20 is connected to or to each controller that is responsible for an adjacent area. A specific controller is not, in preferred embodiments of the invention, connected to a controller that is not responsible for an adjacent area.

The controllers then function in a similar manner to that described in accordance with Figure 1. In this embodiment, the base station controllers and the radio network controllers are the channel allocation entities. Thus, conditions in adjacent or overlapping cells of both networks can be considered when making channel allocation decisions.

Referring to Figure 5, this shows a third embodiment of the present invention. The network shown in Figure 5 is an IP-based radio access network. The area covered by the network is again divided into a plurality of cells 30. Each cell is provided with a base station 32. The base stations 32 are configured to communicate with mobile stations in the associated cell or in other cells. In the network shown on 15

Figure 5, the channel allocation is controlled by the base stations. There may be base station controllers, but they are not responsible for channel allocation. Each base station is connected to the base stations that are responsible for cells that could cause interference to the base station in question.

The base stations then control the allocation of channels in a manner similar to that described in the first embodiment. In the embodiment shown in Figure 5, the channel allocation entities are the base stations.

A description of an exemplary interface configuration for the embodiment of Figure 3 or Figure 5 is performed thereafter. It will be understood that the exemplary interface given herein is for the purpose of illustrating the present invention and that the invention is not limited to this implementation of the interface.

In this example the interface between base station (designated as CRS, cell resource server) and CRS is used for transmitting measurements from base station to neighboring base stations. An exemplary base station measurement is the known channel allocation matrix for the dynamic frequency and channel allocation (DFCA). The CRS-CRS interface is used in order to exchange the information needed by the DFCA so that the main potential gains associated with a synchronized system can be achieved. All channel allocation features that may be potentially constructed over synchronized GSM networks, for example, will preferably be based on the calculation of carrier versus 16 (C / I) values associated with different combinations of the time interval and frequency. In order to accurately perform this calculation it is necessary to access the traffic distribution and power control information of existing connections in interfering cells. This information will allow the system to control the C / I of each connection, efficiently distributing the interference and achieving the highest spectral efficiency.

The interfering cells are allocated to the serving cell CRS and neighboring CRS. Therefore, a mechanism should be provided to access relevant information from neighboring CRS. There are two possible guidelines for implementing this interface. A. Point-to-Point Addressing (UNICAST)

In this case, a measurement message must be generated for each of the neighboring CRSs that should receive the message. B. Multicast Addressing (Multicast Addressing) Multicast addressing can be used so that if a CRS has to send the same measurement to several neighboring CRSs, only one message is sent to a multicast address and the transmission network distributes a copy of the multicast address. message to all recipients. 17

The same elementary processes can be specified for both options, but the only difference will be some of the message content.

The same elementary processes can be specified for both techniques. The only difference will be the message content.

This interface will be based on the common and dedicated measurement processes Iub [25433] and Iur [25423].

In this preferred embodiment, a new CRMS interface (CRS) is provided. The main function of the new CRMS-CRS interface is to transfer measurements from base station to CRMS. One of the most important measurements to report is information related to the actual charge on the cells managed by the CRS.

The measurement notification processes can be based on the Iur Common Measurement processes [25 * 423]. These, and also the Iucl interface, support, upon request (immediate), periodic or event-triggered notification methods. On request (immediate): in this case, the measurements will be sent immediately, as a response to the measurement initiation request message.

Periodicals: measurements are sent periodically, the notification period is fixed in the measurement initiation request message.

Event-triggered: It is also possible to define events or threshold levels, so that the measurements are only sent 18 when a particular event occurs (or if the threshold level is reached). The CRMS-CRS interface allows the CRMS to select and set the notification method for one, a group, or all elements to be measured using only process messages. Notification of measurements can also be done individually or in a group. Measurements can be expressed with parameters independent of the radio technology or sent directly to the CRMS with radio-dependent parameters so that the application running in the CRMS can convert them.

It is assumed that the reference scenario for further standardization is the standard Iub / Iur interface processes. Based on this assumption, four elementary processes are preferably defined for this interface: measurement initiation; measurement notification; measurement completion; and measurement failure.

The measurement notification processes are based on the Iur UTRAN Common Measurement [25423] processes. These processes and also those defined for this interface will support on-demand (immediate), periodic or event-triggered notification methods. The CRMS will select and set the notification method for one, a group or all elements to be measured using only one message. Notification of measurements can also be done individually or in a group.

The measurements can be expressed with parameters independent of the radio technology or only be sent directly to the CRMS with radio-dependent parameters, so that the application running in the CRMS should convert them. You can use either or both of these options.

Four basic processes are defined for this purpose:

Process Result Message Result Mal Elementary Initiation Succeeded Succeeded Timer Message Message Response Response Initiation of RESPONSE FAILURE Measurement INITIATION OF INITIATION INITIATION MEASUREMENT MEASUREMENT MEASUREMENT Notification MEASUREMENT MEASUREMENT NOTIFICATION MEASUREMENT REQUIREMENT Conclusion MEASUREMENT CONCLUSION MEASUREMENT INDICATION failure MEASUREMENT FAILURE

In the measurement initiation illustrated in Figure 6a, the client (i.e., CRMS) sends a MEASURE INITIATION REQUEST message to the IP BTS (CRS) (server). This message defines which object (s) will be measured and the notification characteristics, which are: 20 On request (immediate): In this case, the measurements will be sent immediately, as a response to the INITIATION ORDER message OF MEASUREMENT. - Periodic: the measurements are sent periodically, the notification period is fixed in the MEASUREMENT INITIATION REQUEST message.

Event-triggered: It is also possible to define some type of events or threshold levels, so that measurements are only sent when this event occurs (or reaches the threshold level).

If the operation is successful, the IP BTS (server) sends a MEASURE INITIAL RESPONSE message, which can include the measurement if the on-demand option has been configured. On the other hand, if the operation is unsuccessful, the IP BTS (CRS) (server) sends a MEASUREMENT INITIATION FAIL message, which will include the cause of this failure.

We will now discuss the measurement notification using Figure 6b.

This process is used by the client (IP BTS (CRS)) to communicate the measurements requested by the CRMS in the Measurement Initiation process.

We will now discuss the measurement completion using Figure 6c. The CRMS (client) sends a MEASUREMENT CONCLUSION REQUEST to an IP BTS (CRS) (server) indicating which measurement or group of measurements will be completed. No response is required for this process.

We will now discuss the measurement failure using Figure 6d.

A MEASUREMENT FAILURE INDICATION is sent by an IP BTS (CRS) (customer) to inform you that a previously requested measurement can no longer be reported. This message includes the cause of failure. Figure 6 (e) illustrates a measurement failure. A measurement failure indication is sent by a CRS to inform you that a previously requested measurement can no longer be reported. This message includes the cause of failure.

Using a new CRMS-UCF interface (user equipment control function), the UCF sends to the CRMS (server) the list of candidate cells of a mobile station for a specific operation (transfer, cell change order ... ), including (if available) mobile measurements for these cells and information on the quality of service that the user requires. The CRMS (server), after applying some algorithms, returns the list with priority assignment.

As shown in Figure 6e, the client (ie, transmit-receive base station based on IP Internet Protocol BTS (UCF)) sends a REQUEST OF LIST OF CELLS TO WHO HAS BEEN ASSIGNED PRIORITY, including, as parameters, the list of candidate cells, the mobile measurements for these cells, information about the class of mobile station and the quality of the service parameters required by the user for the operation. If the priority assignment is completed successfully by the CRMS (server), it sends a PRIORITY ASSIGNED CELL LIST RESPONSE message, which includes the list of reordered candidate cells. In the event of an unsuccessful operation, the CRMS should send a message CELL LIST FAILED TO WHOM PRIORITY WAS ASSIGNED, with cause of failure (CRMS error, measurement of cell load not available or similar ...).

If you do not receive the CELL LIST REPLY message to whom PRIORITY IS ASSIGNED, or if you receive the message CELL LIST FAILURE TO WHOM PRIORITY IS ASSIGNED, it is assumed that the customer will make the transfer decision only on the basis of the measurements MS. If the CELL LISTING RESPONSE WHO IS ASSIGNED PRIORITY to arrive correctly, the client must adopt this message as a command and attempt to transfer to the first candidate cell of the list with priority assignment, if this fails, the client will try with the second candidate cell in the list, and so on. The OMS (operation and management server) - CRMS interface is the interface between the CRMS (client) and O & M server. It has two different functions. First, allow the client to change parameters on network elements (e.g., Node B, RNC) by requesting these changes to the O & M server. This is a more controlled way than changing the parameters directly in the network elements. Second, allow the client to read the configuration management parameters.

Two elementary processes are defined for this interface, as described below. Figure 6 (f) illustrates a change of parameters. The client 23 sends a parameter change request to the parameter server. It includes the identification of the entity whose parameters are to be changed and the new parameter values. Consequently, if the parameter values are changed correctly, the parameter server will respond with a parameter change response message. On the other hand, if the operation is unsuccessful, the parameter server sends a parameter change failure message, including the cause of the failure (eg, parameters not available, bad parameter value, unauthorized change). Figure 6 (g) illustrates a reading of configuration management parameters. The client sends a request message to read CM parameters (configuration management), which includes the list of parameters to be read. If the operation is successful, the parameter server responds with a CM parameter read response, including the parameters requested by the client. On the other hand, if the operation is unsuccessful, the Parameter server will send a CM parameter read failure message containing the cause of the failure. The DFCA method will now be described in more detail. The DFCA is a channel assignment scheme for CSW circuit-switched traffic using mobile downlink metering notifications and interference estimates for the downlink and uplink to dynamically allocate a time and frequency interval in establishing a call new The criteria for this channel selection are to provide high quality in terms of the carrier-to-interference ratio (C / I), which leads to each connection meeting its quality of service requirements, reducing interference from other connections.

This leads to a significant gain in capacity as the consumption of valuable frequency resources is dynamically optimized. The DFCA is an automated feature that suppresses the need to make a frequency plan for the transceivers that work with this new functionality. The effect of this feature on the C / I distribution is similar to other capacity enhancement features such as power control, frequency hopping and Intelligent Underlay-Overlay IUO technology. The connection level C / I control ensures that a high proportion of the connections is within a desired C / I window.

In order to achieve this, a time interval synchronization (TSL) level is required. In other words, all the time intervals of the different base stations begin and end at the same time.

This level of TSL synchronization for the base stations allows the BSC to be aware of the sources of interference when a new channel assignment is to be performed and thus, combining this information with the time interval and the frequency usage allows a channel selection. The information related to the expected potential interference situation for a particular connection comes mainly from notifications of measurement of mobile discharges (provided every 480 ms). However, due to the limited information contained in the actual measurements provided by the mobile stations (only the six strongest neighbors are notified), for this purpose some statistical estimation of the interference situation must be implemented. This can be done by means of a Matrix of 25

Thus, each cell in the network considered as a DFCA cell would have this information structure in order to estimate the impact in terms of interference caused by other DFCA cells in the downlink and uplink directions. It is preferred that the base station controller to base station controller interconnect be a DFCA interconnect.

In some embodiments of the invention, DFCA may be used with other existing features, such as power control and frequency hopping. In the example of frequency hopping, only the cyclic mode will be implemented for the DFCA and thus this brings the frequency gain.

The advantages of DFCA are: enhanced quality of service control - addressing different classes of CSW traffic (voice, HSCSD high speed circuit switched data) and providing means of differentiation between users; operating costs are reduced if DFCA is operating on more transceivers, as less frequency planning is required to configure the network.

A more detailed description is now given, referring to Figure 7, of how one or more of the above-described embodiments may be implemented. The BSC-BSC interface is used for the transmission of BSC or BTS measurements to neighboring BSCs, for example, the BIM channel allocation matrix for the DFCA. 26

As previously mentioned, the DFCA is a way of allocating and controlling the air interface capabilities used for each connection based on the type of service required, so that the required quality of service is provided and no resources are wasted by delivery of quality in excess of users and services that do not need it. The radio resource management system maintains an array of the connection quality of all possible time intervals and frequencies at which each connection request can be allocated. This matrix gives a choice of possible proportions of C / I that can be allocated. The algorithm looks for a pair (time interval, frequency) in which the required C / I level matches the required quality. The BSC-BSC connection is necessary in order to exchange the information required by the DFCA in order to achieve the main potential gains associated with a synchronized system. All Channel Allocation features that can be potentially built through Synchronous GSM networks will be based on the calculation of C / I values associated with different combinations of time interval and frequency. In order to accurately perform this calculation, it is necessary to access the traffic distribution information and power control of existing connections in interfering cells. This information will allow the system to control the C / I of each connection, efficiently distributing the interference and achieving the highest spectral efficiency.

Interference cells can be controlled by the service cell BSC or a neighboring BSC. Therefore, a mechanism for accessing relevant information from neighboring BSCs 27 should be implemented. This interface is compatible with the CRS-CRS interface in the IP-RAN architecture described above. In preferred embodiments of the invention, the BSC-BSC interface has elementary processes the same or similar to those of the CRS-CRS interface. There are two possible options for implementing this interface. A) Point-to-Point Addressing (UNICAST)

In this case, a measurement message must be generated for each of the neighboring BSCs receiving the message. B) Multicast addressing (Multicast) Multicast addressing can be used so that if a BCS has to send the same measurement to several neighboring BSCs, only one message is sent to a multicast address and the transmission network distributes a copy of the multicast address. message to all recipients.

The same elementary processes can be specified for both options. The only difference will be some of the message content. The transport layer will also provide some mechanisms in order to detect if the connection between two BSCs is not functioning and inform an upper layer of this situation. 28

Four processes are specified for this interface. The first process establishes a new measurement relationship between a source cell in the source BSC and a destination cell in the destination BSC. The Measurement Ratio Initiation process also initiates the sending / exchanging of measurements between the source BSC and the destination BSC related to the source and destination cell, respectively. The Relation type information element IE indicates the relationship type. The type of measurements to be switched will depend on this Relation type IE (for example, in the specific case of the DFCA relation, a measurement relation will be established when the destination cell appears in the BIM matrix of the source cell. are: " channel assignment / release " in the source cell, " channel assignment / release " in the target cell, " updating BIM " from the source cell to the destination cell and " cell "). The measuring ratio is defined in one direction only; therefore, the target cell-source cell relationship is different from the target cell-source cell relationship.

A MEASUREMENT RATE INITIATION REQUEST message is sent from the source BSC to the destination BSC when the measurements between the origin and destination BSCs related to the source and destination cells respectively must be sent / exchanged (in the case of DFCA measurements, when a source BSC cell detects a new BIM entry of a cell from an external BSC). The purpose of this message is to establish the measurement relationship between those two cells. The MEASUREMENT RATIO INITIATION REQUEST must include the identification of the source cell (DFCA: the cell where the entry 29 appeared), the destination cell ID (DFCA: the cell that appeared in the BIM), and Relation Type IE , which indicates the type of measurements to be changed. This message also includes the list of source cell-related metrics that the source BSC supports, including the notification characteristics and, in the case of measurements sent using multicast addressing, the multicast IP address.

If the operation is successful, the destination BSC will generate a MEASUREMENT RATE INITIATION RESPONSE message. This MEASUREMENT RATE INITIATION RESPONSE message also tells the originating BSC what parameters are required to receive target BSC-related cell count measurements as defined in the Relay Type IE.

Upon receipt of the MEASUREMENT RATE INITIATION RESPONSE message, the measurement (Measurement Notification process) exchange between the source BSC and the destination BSC related to the source and destination cell respectively, begins.

If the multicast option is used, the MEASUREMENT RELAY INITIATION REQUEST message will include the source cell multicast transport address so that the destination BSC can use it to receive cell-related measurements from origin of the BSC.

If the multicast option is used, the MEASUREMENT RATE INITIATION RESPONSE message will include the destination cell multicast transport address so that the source BSC can use it to receive the cell-related measurements destination BSC. 30 Ο ΙΕ is used to inform the source / destination BSC of the type of notification by which measurements are to be sent.

In the case of a specific measurement defined in the Measurement Type IE, the event-X option can be used by setting the specific threshold values. In the case of a group of measurements defined in the Measurement Type IE, the event-X options will only be used for a specific parameter. In the case where no specific parameter is defined, the C-event option can be used, with the increase / decrease threshold 0, indicating that the measurements will be communicated whenever there is a change in the state of the group of measurements defined in the IE of Type of Measurement. (For example, if the Measurement Type IE is set to " Channel Assignment / Release ", the Notification Feature IE is set to " Event-C " and the increase / decrease threshold is set to 0, indicating that assigned / released channels are sent whenever there is a channel assignment / channel release).

In the case of DFCA measurements, the MEASUREMENT RELAY INITIATION REQUEST message (corresponding to the first BIM update message) is sent to all BSCs belonging to the destination cell location area. Thus, BSCs that do not have the destination cell that received the MEASUREMENT RELAY INITIATION REQUEST message will ignore this request and only the cell's BSC owner will generate the MEASUREMENT RELAY INITIATION FAIL / FAIL message.

We now turn to Figure 7B. If the requested measurement ratio can not be initiated, the destination BSC will send a message MEASUREMENT RELAY INITIATION FAIL, which must include the cause of this fault.

The typical values of the cause are as follows:

Measurement not supported for the object; or DFCA not supported for the cell.

Referring to Figure 7C, this shows the process used by a BSC to communicate the result of measurements requested by the relationship created in the measurement ratio initiation process. In the case of the DFCA, the requested measurements are those related to the channel state of the source and target cells of the relation, the BIM update measurements of the source cell and the cell information change.

This process is used by the BSC to perform the multicast / notification of the measurement related to one cell to the other BSC that requested the measurements.

If the Metering Type IE is set to " Channel Assignment / Release ", a MEASUREMENT NOTIFICATION message shall be generated from each of the BSCs whenever there is a channel assignment or a channel release in a cell involved in a relation. This message should be issued to all source BSCs that have cells with relations established with this cell. Even if there is more than one relationship between the destination cell and cells of a BSC, only one MEASUREMENT NOTIFICATION message must be sent to the source BSC. 32

If the Measurement Type IE is set to " BIM Update ", a MEASUREMENT NOTIFICATION message must be generated from the source BSC to the destination BSC containing the destination cell whenever there is a change in the value of interference in the matrix BIM. This message is sent using point-to-point addressing and contains the new C / I value measured in the source cell for the destination cell.

If the Measurement Type IE is set to " Cell Information Change ", a MEASUREMENT NOTIFICATION message shall be generated from the source BSC to the destination BSC to indicate that the source cell BCCH or BSIC has been changed by the operator.

Referring to Figure 7D, this shows the process used by a BSC to terminate a measurement relationship previously requested by the Measurement Ratio Initiation process. The source BSC will send a MEASUREMENT RELATIONSHIP REQUEST to the destination BSC, indicating that the relationship ID identified by the Rel Rate Id will be terminated due to some cause. Upon receipt, the destination BSC must terminate the established relationship between the source cell and the destination cell. No response is required for this process. The completion of the measurement relationship also implies (in the case of there being no relation in the destination cell-destination cell route) the completion of the measurement process between the source cell and the destination cell. 33

A DFCA relation initiation request will generally include the following information: message type; transaction identity; base station controller identity; the BSIC for the interfered cell; the BCCH for the interfering cell; the BSIC for the interfering cell; the BCCH for the interfering cell; the CIM value of BIM; the type of measurement that is supported in the source cell; the notification characteristics supported in the source cell, and if multicast addressing is supported, the class D address of the source cell is provided. The DFCA ratio initiation response may include information similar to that of the DFCA ratio initiation request. However, the measurement type and notification characteristics will be those that are supported by the destination cell and not by the source cell. The multicast IP address will be that of the destination cell.

If the DFCA relation initiation fault is the response, then this will include the message type; the transaction identity; the identity of the interfered cell; the BSIC for the interfered cell; the BCCH for the interfering cell; the identity of the interfering cell; the BSIC of the interfering cell; interfering cell BCCH; and the cause of failure. The BIM update message includes the following information elements; type of message; transaction identity; identities of interfering and interfering cells, BSIC and BCCH; and the BIM value C / I. The measurement notification message will include the following: message type; transaction identity; the BSIC and BCCH of the cell; the type of measurement supported in the cell; channel assignment / release measurements; channel operation; channel information; channel type; subchannel; connection time interval; transmitter identity; the mobile allocation MA-normalized ID list MAY]; training sequence code; power control information; and carrier relationship versus minimum channel interference required. At least some of these information elements may be optional. The DFCA relationship completion request may include the following: message type; transaction identity; interfering cell and interfering cell identities and their BSIC and BCCH. The transaction identity is used to associate all messages belonging to the same process. Messages belonging to the same process must use the same transaction identity. The measurement type identifies the type of measurement to be performed. The channel operation indicates that the operation included is a channel assignment or a channel release. The notification characteristics indicate how the measurement notification should be performed. For example, notification can be made on demand, periodically, in which case the period is specified, or in response to the occurrence of an event, and the event parameters are defined. The event may be in response to a particular measured threshold reached. Different events may have different thresholds.

It is to be understood that embodiments of the invention not using the DFCA process may contain information in their messages similar to those of the DFCA process. 35

It should be understood that the network of Figure 5 can be used in systems where there is more than one network. Other networks may be of the type shown in Figure 4. In this case, the base stations of the network shown in Figure 5 would be connected to the base station controllers of a GSM network or to the radio network controllers of a CDMA network.

It is to be understood that the modification of the first embodiment shown in Figure 3 may be used with the second or third embodiments.

It is to be understood that embodiments of the invention are applicable to GSM base station controllers or any similar entity in any other type of network, for example a cell resource server in an IPR radio access network. Embodiments of the present invention have been described in the context of the DFCA algorithm. However, the embodiments of the present invention may be used in any situation where there is a need for information exchange around neighboring cells. The embodiment described hereinbefore proposes a mechanism for exchanging information relating to cells belonging to different cell controllers or base station controllers. The described mechanism can use IP multicast services. The requirement for measurements from the destination cell in the source cell can be triggered by any appropriate event, such as mobile station measurements, operator configuration or the like. In the case of the DFCA, the channel allocated or released in the destination cell is required in the source base station controller when the received mobile station measurements indicate that the destination cell is interfering with users in the source cell.

If the multicast option is used, class D IP addresses are used. Thus, if a base station controller or similar wants to receive measurements related to the external cell, it must inform its local router that it wants to receive transmissions addressed to the multiple groups external cell. This subscription can be made using the IGMP internet group management protocol. If the base station controller or similar wants to receive measurements related to an external cell, it needs the IP multicast address of that external cell. The reply message includes the multicast IP address of the destination cell so that the source base station controller can initiate the sign-up process on its local router. In addition, the request address includes the multicast IP address of the source cell so that the destination base station controller can also receive the measurements related to the source cell by performing the same subscription process.

With the multicast option, it is preferred that the local route supports the IGMP protocol.

In embodiments of the present invention, mobile stations have been described. It should be understood that the mobile stations may be replaced by any other suitable user equipment which may or may not be mobile.

Lisbon, March 6, 2012 37

Claims (32)

A first means configured to control the allocation of wireless channels to at least one station (8) movable in a portion (4, 30) of a cellular wireless communication system covering an area, characterized in that it is configured to send information relating to the allocation of wireless channels in the portion (4, 30) of the area associated with said first means (10, 20, 32), which information allows controlling the carrier-to-interference ratio of connections, for at least one another from a plurality of first means (10, 20, 32) configured to control the allocation of wireless channels to at least one station (8) movable in a portion (4, 30) of a cellular wireless communication system covering an area and which is associated with a part of said area adjacent to and close enough to cause interference or at least partially overlapping the part of the area associated with said first means. The first means (10, 20, 32) as claimed in claim 1, wherein said first means is provided with information identifying the at least one first means (10, 20, 32) for which to send said information regarding the allocation of wireless channels. The first means (10, 20, 32) according to any one of claims 1 to 2, wherein the information relating to the allocation of wireless channels is multi-diffused. 1 The first means (10, 20, 32) as claimed in any one of claims 1 to 3, wherein said first means is configured to continuously send said wireless channel allocation information to said less one, another first means (10, 20, 32). The first means (10, 20, 32) as claimed in any one of claims 1 to 3, wherein said first means is configured to send said wireless channel allocation information when there is a change in said relative information to wireless channel allocation. The first means as claimed in any one of claims 1 to 3, wherein said first means is configured to send said wireless channel allocation information in response to a request from one of said at least one one, further first means (10, 20, 32). The first means (10, 20, 32) as claimed in any one of claims 1 to 6, wherein said first means is configured to send said wireless channel allocation information to a coordination means (12) , wherein said coordinating means (12) is provided in a web element separate from said at least one first first means (10, 20, 32). The first means (10, 20, 32) as claimed in any one of claims 1 to 7, wherein said portion (4, 30) of said area is a source and said other portion (4, 30) of said area is a destination. 2 The first means (10, 20, 32) as claimed in claim 8, comprising a means for sending a message to one of said at least one other first means (10, 20, 32) associated with said destination to start the communication. The first means (10, 20, 32) as claimed in claim 9, wherein said message contains one or more of the following information elements: message type; transaction identity; identity of said origin; information on parameters at source and / or destination; information regarding a carrier versus interference relationship; types of measurement supported on said origin or on the first medium associated with said origin; notification features supported by said origin or said first medium associated with said origin; if multicast addressing is used, the address of said source or the first medium associated with said source. The first means (10, 20, 32) as claimed in claim 9 or claim 10, comprising a means for receiving a response message from the first means from one of said at least one other first means (10, 20 , 32) associated with said destination. A first means (10, 20, 32) configured to control the allocation of wireless channels to at least one mobile station (8) in a portion (4, 30) of a cellular wireless communication system covering an area , Characterized in that it is configured to take into account information which is received from at least one other of a plurality of first means (10, 20, 32) and which relates to the allocation of channels in the part (4, 30) of the area associated with said at least one first means (10, 20, 32), which information allows controlling the carrier-to-interference ratio of connections, when controlling the allocation of wireless channels in the portion of the area (4, 30) associated with the at least one other first means (10, 20, 32) that is associated with a portion of said area adjacent and close enough to cause interference or at least partially overlapping the part of the area associated with said first medium. The first means (10, 20, 32) as claimed in claim 12, comprising a means for sending to said at least one other first means (10, 20, 32) a request for said information. The first means (10, 20, 32) as claimed in any one of claims 12 to 13, comprising means for receiving said information through a coordination means (12), wherein said coordination means (12) is provided on a separate network element of said at least one other first means (10, 20, 32). The first means (10, 20, 32) as claimed in any one of claims 12 to 14, wherein said portion (4, 30) of said area is a target and said other portion (4, 30) of said area is an origin. 4 The first means (10, 20, 32) as claimed in claim 15, comprising a means for receiving a message from one of said at least one other first means (10, 20, 32) associated with said origin to start the communication. The first means (10, 20, 32) as claimed in claim 16, comprising a means for sending a response message to said at least one other first means (10, 20, 32) associated with said origin . The first means (10, 20, 32) as claimed in claim 17, wherein said response message includes one or more of the following information elements: message type; transaction identity; identity of that objective; information on parameters at source and / or destination; information regarding a carrier versus interference relationship; types of measurement supported at said destination or in the first medium associated with said destination; notification features supported by said destination or first means associated with said destination; if multicast addressing is used, the address of said destination or the first medium associated with said destination. The first means (10, 20, 32) as claimed in claim 17, wherein said response message, if it is not possible to establish said communication, comprises a cause of failure. 5 The first means (10, 20, 32) as claimed in any one of claims 1 to 19, wherein said wireless channel allocation information comprises power control information. The first means (10, 20, 32) as claimed in any one of claims 1 to 20, wherein said wireless channel allocation information comprises cell information and / or wireless channel allocation information. The first means (10, 20, 32) according to claim 21, wherein the cell information includes information for identifying the cell. The first means (10, 20, 32) according to claim 21 or 22, wherein the wireless channel allocation information includes the state of time slots, e.g., inactive, reserved, half of the throughput or total throughput, base station power control used in downlink, or the rate allocation index shift to the mobile used. A first means as claimed in any one of claims 1 to 23, wherein said first means comprises a base station (32). A first means as claimed in any one of claims 1 to 23, wherein said first means comprises a base station controller (10) or a radio network controller (20). 6 as A first means as claimed in any one of claims 12 to 23, wherein said first means comprises a coordinating means (12), wherein said coordinating means (12) is provided on a separate network element of said, at least one, another first means (10, 20, 32). The first means (10, 20, 32) as claimed in any one of claims 12 to 26, wherein said first means (10, 20, 32) is configured to use one of the following methods: dynamic frequency allocation; dynamic channel allocation; and coordination of the use of high data rates. The first means (10, 20, 32) as claimed in any one of claims 1 to 27, wherein said first means (10, 20, 32) is associated with a first radio access network (16) and the (10, 20, 32) is associated with a second, different radio access network (18). The first means (10, 20, 32) as claimed in any one of claims 1 to 28, wherein said wireless channel assignment information comprises: uplink background noise interference matrix information and link downward; or a channel allocation matrix. A wireless cellular communication system covering an area, said system comprising a plurality of first means (10, 20, 32), each of said first means being configured to control the allocation of wireless channels to, (10, 20, 32) is a first means according to claim 1, characterized in that at least one of said first means (10, 20, 32) is movable in a portion (4, 30) of said area; wherein said at least one other of said first means (10, 20, 32) is a first means according to claim 12. A method for controlling the allocation of wireless channels in a first channel allocation entity (10, 20, 32) which is configured to send wireless channel allocation information in the area (4, 30) of the area associated with the channel said first channel allocation entity, the method comprising: controlling the allocation of wireless channels to at least one station (8) movable in a portion (4, 30) of an area covered by a cellular wireless communication system; characterized in that the method comprises sending information relating to the allocation of wireless channels in said portion (4, 30) of the area associated with said channel allocation entity (10, 20, 32), which information allows controlling the relationship (10, 20, 32), said channel allocation entity (10, 20, 32) configured to control the allocation of wireless channels (10, 20, 32) to the at least one channel allocation entity in another portion (430) of the area and which is associated with a portion of said area adjacent to and near enough to cause interference or at least partially overlapping with the part of the area associated with said first entity (10, 20, 32 ) of allocation. A method of controlling the allocation of wireless channels in a first channel allocation entity (10, 20, 32), which is configured to take into account information received from at least one other entity (10, 20, 32) (4, 30) of the area associated with said channel allocation entity (10, 20, 32), the method comprising: controlling the allocation of wireless channels for at least one station (8) movable in a portion (4, 30) of an area covered by a cellular wireless communication system; characterized in that said allocation control is carried out as a function of information received from at least one other channel allocation entity (10, 20, 32) relative to the allocation of wireless channels in another part (4, 30) of the area associated with said other channel allocation entity (10, 20, 32), which information allows controlling the carrier-to-interference ratio of connections and channel allocation entity (10, 20, 32) which is configured to control the channel allocation entity allocation of wireless channels in said other portion (4, 30) of said area and which is associated with a portion of said area adjacent and close enough to cause interference or overlap, at least partially, to the part of the associated area with said first channel allocation entity (10, 20, 32). 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