WO2012093138A1

WO2012093138A1 - A method of releasing resources (e-rnti) in a communications network

Info

Publication number: WO2012093138A1
Application number: PCT/EP2012/050082
Authority: WO
Inventors: Masatoshi Nakamata; Minna Maria NEVALAINEN
Original assignee: Nokia Siemens Networks Oy
Priority date: 2011-01-05
Filing date: 2012-01-04
Publication date: 2012-07-12
Also published as: EP2661940A1

Abstract

A method of managing resources in a communications network is provided. The method includes sending a resource release request from a control node, receiving the resource release request at a network node, processing a resource release based on the resource release request at the network node, and reporting an outcome of processing to the control node.

Description

DESCRIPTION TITLE

A METHOD OF RELEASING RESOURCES (E-R TI) IN A COMMUNICA IONS NETWORK

FIELD OF THE INVENTION

The invention generally relates to a method of manag^¬ ing resources in a communications network. More par^¬ ticularly, the invention relates to an enhanced method for radio resource management in a Node B.

BACKGROUND OF THE INVENTION

Currently, in the 3GPP standard, if a controlling ra^¬ dio network controller (CRNC) requests a resource re^¬ lease from the Node B, the request may be lost due to a processing error, either in the Node B itself or on a transmission link. If the request is lost, the re^¬ source may never be released in the Node B. This causes an ID for a mobile station or user equipment (UE) to be lost and therefore reduces the number of UEs in the cell.

This problem may be solved currently by using a timer, whereby the resource is released upon expiry of the timer. However, this is an unreliable solution, since the Node B does not know whether the resource; i.e. the Enhanced Dedicated Channel Temporary Network Iden^¬ tifier (E-RNTI) would still be needed by the UE . Therefore it improves the resource release but intro^¬ duces a new problem if the resource is released too early. A time period for resource usage cannot be predicted by the network when a UE enters a cell.

The invention seeks to provide a solution to the above-mentioned problems.

SUMMARY OF THE INVENTION

Accordingly, the invention provides a method of manag^¬ ing resources in a communications network. The method includes sending a resource release request from a control node, receiving the resource release request at a network node and processing a resource release based on the resource release request at the network node .

The control node informs the network node that the re^¬ source is no longer needed in the network node and sends a resource release request to the network node. When the network node receives the resource release request, it processes release of the radio resource indicated by the resource release request. The net^¬ work node can then indicate the outcome of the re^¬ source release to the control node.

In this way, the network node is able to provide a feedback to the control node, which indicates an out^¬ come of the resource release requested by the control node. This provides the advantage of a synchronised status between the control node and the network node so that that resource release requests are not lost by the network and resources are not released too early, thereby conserving IDs for UEs located in the cell.

Preferably, the step of processing comprises releasing or not releasing a resource indicated in the resource release request. The network node may either release the resource indicated in the resource release request received from the control node, if the resource was allocated to a particular UE and is no longer required by the UE (for example if the UE is no longer in the cell) or it may not release the resource (for example if the UE is still in the cell and requires the re^¬ source) . The resource may be an ID allocated to a UE, for example an E-RNTI.

The method may further include reporting an outcome of processing to the control node. The step of reporting may include sending an acknowledgement related to the request if the resource is released or sending a fail^¬ ure message related to the request if the resource is not released.

In one embodiment, a processing operation is performed at the control node based on the reported outcome of processing. For example, the control node may repeat the resource release request if it receives feedback that the resource release was not performed by the network node. The control node can correlate feedback message (s) from the network node reporting an outcome of the resource release to an earlier resource release request .

In another embodiment, the step of performing a proc^¬ essing operation includes completing a resource release procedure in the control node if reporting the outcome of processing indicates that the resource was released during the step of processing the resource release. The control node may complete the resource release process if it receives feedback that the net^¬ work node released the resource in response to the re^¬ source release request.

In a further embodiment, the step of performing a processing operation includes repeating sending the resource release request if reporting the outcome of processing indicates that the resource was not re^¬ leased during the step of processing the resource re^¬ lease. The control node can repeat its resource re^¬ lease request to the network node if it receives feed^¬ back that the resource was not released by the network node .

The resource release request may be common to multiple mobile stations.

The invention also provides a method of managing re^¬ sources in a communications network, which includes receiving a resource release request and processing the resource release based on the resource release re^¬ quest .

The step of processing may include releasing or not releasing a resource indicated in the resource release request .

The method may further include reporting an outcome of processing of the resource release. The step of re^¬ porting may include sending an acknowledgement related to the request if the resource is released or sending a failure message related to the request if the re^¬ source is not released.

The invention further provides a method of managing resources in a communications network. The method in^¬ cludes sending a resource release request and

performing a processing operation depending on an outcome of the processing of the resource release.

Performing a processing operation may include completing a resource release procedure if the resource was released in response to the resource release request.

Alternatively, the step of performing a processing op^¬ eration may include repeating sending the resource re^¬ lease request if the resource was not released in re^¬ sponse to the resource release request.

The method may further include receiving a report of an outcome of processing of a resource release based on the resource release request. In this way, a syn^¬ chronized status between a network node and its con^¬ trol node may be maintained and the control node has information as to whether a resource was released or not in response to its request. In this way, re^¬ sources that are no longer needed may be re-used.

In another aspect, the invention provides a network node. The network node includes a receiver configured to receive a resource release request. A processor is configured to process a resource release based on the resource release request. In one embodiment, the processor is configured to re^¬ lease a resource or not release the resource based on the resource release request received at the receiver.

The resource may be an ID of a mobile station or user equipment (UE) , in particular an E-RNTI, for example. If the UE is no longer in the same cell as the network node, then it no longer needs the E-RNTI. In this case, the processor of the network node can then release the ID to be re-used for another UE in the cell. If however the UE is still in the same cell as the network node, it still requires the E-RNTI and the processor of the network node will then not release the E-RNTI.

A transmitter may be provided, which can be configured to send a message reporting an outcome of processing of the resource release.

The message sent by the transmitter may contain an ac^¬ knowledgement related to the request if the resource is released by the processor.

Alternatively, the message sent by the transmitter can be a failure message related to the request if the re^¬ source is not released by the processor.

The network node may be a base station or a Node B, for example.

In a further aspect, the invention provides a control node. The control node includes a transmitter config^¬ ured to send a resource release request. A processor is configured to perform a processing operation de- pending on the outcome of the processing of the re^¬ source release received in the report.

The processing operation performed by the processor may include completing a resource release procedure if the the resource was released in response to the re^¬ source release request.

Alternatively, the processing operation performed by the processor may include repeating sending the resource release request if the resource was not re^¬ leased in response to the resource release request.

A receiver may be provided, which can be configured to receive a report of an outcome of processing of a re^¬ source release based on the resource release request. This provides the advantage that the control node can obtain feedback as to whether or not a resource was released in response to its request and may re^¬ allocate the resource accordingly. Alternatively, if the receiver does not receive feedback, this can indi^¬ cate to the control node that the resource release re^¬ quest was processed successfully and the resource was released .

The control node may be a base station controller or a radio network controller (RNC) , in particular a controlling RNC (CRNC) , for example.

In a further aspect of the invention, a communications network is provided. The communications network in^¬ cludes a control node, which is configured to send a resource release request, and a network node, which is configured to receive the resource release request from the control node and to process a resource re^¬ lease based on the resource release request.

The network node may be further configured to report an outcome of processing to the control node.

The invention will now be described, by way of example only, with reference to specific embodiments, and to the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a simplified schematic block diagram of a communications network according to an embodiment of the invention;

Figure 2 is a simplified schematic block diagram of a network node according to an embodiment of the invention;

Figure 3 is a simplified schematic block diagram of a control node according to an embodiment of the inven^¬ tion;

Figure 4 is a flow chart illustrating a method accord^¬ ing to an embodiment of the invention;

Figure 5 is a flow chart illustrating a method accord^¬ ing to an embodiment of the invention;

Figure 6 is a message flow diagram illustrating a method according to an embodiment of the invention; and Figure 7 is a message flow diagram illustrating a method according to an embodiment of the invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Figure 1 shows a radio access network (RAN) 1, which is shown here as a UMTS network according to the 3GPP standard .

The RAN 1 includes a Node B 2 controlled by a radio network controller (RNC) 3 over an Iub interface. The RNC 3 is specifically a controlling RNC (CRNC) and in reality it may control several Node Bs provided in different cells of the RAN 1.

A mobile station or user equipment (UE) 4 can access the RAN 1 via the Node B 2, which provides access to one cell CI of the RAN 1.

The Node B 2 is shown in more detail in Figure 2 and includes a transmitter Txl, a receiver Rxl and a processor PI. The receiver Rxl is configured to receive a resource release request from the RNC 3. The proces^¬ sor PI is configured to process a resource release based on the resource release request and the trans^¬ mitter Txl is then configured to send a message to the RNC 3 reporting an outcome of processing of the resource release by the processor PI.

Figure 3 shows the RNC 3, which includes a transmitter Tx2, a receiver Rx2 and a processor P2. The transmitter Tx2 is configured to send a resource release re^¬ quest to the Node B 2. The receiver Rx2 is configured to receive a report from the Node B 2 of an outcome of processing of a resource release based on the resource release request. The processor P2 is configured to perform a processing operation depending on the outcome of the processing of the resource release re^¬ ceived in the report.

A flow chart illustrating a method according to one embodiment of the invention is shown in Figure 4. In step SI the RNC 3 sends a resource release request message from the transmitter Tx2 to the Node B 2. The resource release request requests the Node B 2 to re^¬ lease resources for indicated E-RNTIs; i.e., for the E-RNTI associated with the UE 4. Although this embodiment is described with reference to just one UE 4, the resource release request can in fact be a common message and not a procedure dedicated to one UE - it can be used for releasing multiple UEs.

The Node B 2 receives the resource release request message at the receiver Rxl in step S2. The processor PI processes a resource release based on the resource release request from the RNC 3 in step S3. . In step S4 the Node B 2 reports the outcome of processing of the resource release performed in step S3 to the RNC 3; i.e., the Node B 2 sends a message to the RNC 3 from the transmitter Tx 1 indicating the E-RNTI associated with the UE 4 was released and can be re-used for an^¬ other UE.

Another embodiment of the invention is illustrated in the flow chart shown in Figure 5. In step Sll, the RNC 3 sends a resource release request to the Node B 2 from the transmitter Tx2, which requests the Node B 2 to release the resource for the E-RNTI associated with the UE 4. The Node B 2 receives the resource release request from the RNC 3 at the receiver Rxl in step S12. In Step 13, the processor PI in the Node B 2 processes the resource release request by determining if all E- RNTIs requested to be released in the resource release request can be released or not. If all E-RNTIs cannot be released, in step S14 the Node B does not release the resource for the E-RNTI of the UE 4 and sends a failure message to the RNC 3 in step S15. The failure message indicates to the RNC 3 that the Node B 2 did not release the resource for the E-RNTI of the UE 4. In this case, when the RNC 3 has received the failure message, it repeats the sending of the resource re^¬ lease request in step S16.

If the processing in step 13 determines that all E- RNTIs can be released, for example, then in step S17, the Node B 2 releases the resource for the E-RNTI of the UE 4 since this is no longer required. In step S18 the Node B 2 sends an acknowledgement message to the RNC 3, which tells the RNC 3 that the resource has been released for the E-RNTI of the UE 4. In step S19 the RNC 3 then completes the resource release process^¬ ing and the E-RNTI can be re-used for another UE in the cell CI.

In one embodiment, a new NBAP Class 2 message is in^¬ troduced for replying to the existing Class 2 message: UE STATUS UPDATE COMMAND already defined in 3GPP. This is illustrated in the message flow diagram shown in Figure 6.

At the first Common E-DCH resource configuration, the RNC 3 includes a new IE in the relevant IE group in the resource configuration message sent from the RNC 3 to the Node B 2. This is shown in Table I and is the IE in the last row of table. The IE requests the Node B 2 to send the Class 2 message if this is supported by the Node B

Table I

Command

If the Node B 2 supports the new Class 2 message, the Node B 2 includes a new IE into the relevant IE Group in a message sent from the Node B 2 to the RNC 3. This IE is shown in the last row of Table II. The new IE

informs the RNC 3 that the Node B 2 accepts the re^¬ quest to send the new Class 2 message.

Table II

E-RNTI List 9.2.2.139 The Node B shall YES ignore not allocate any E- RNTIs listed in this

IE for a UE

UE Status Update Confirm O BOOLEAN TRUE means that YES ignore Support Indicator NodeB supports

UE Status Update

Confirm

After Common E-DCH operation is started, the Node B 2

receives the UE STATUS UPDATE COMMAND message from the

RNC 3 with a list of E-RNTIs for which the allocated

resource is released.

When the Node B 2 has carried out a successful proc^¬ essing of the request to release a resource, the Node

B 2 sends the new Class 2 message to the RNC 3.

In the event that processing is not successful and the

resource is not released, the Node B 2 does not send

the new Class 2 message. In other words, for the Class 2 procedure, no failure message is required. If the RNC 3 does not receive a response from the Node B 2, this indicates that processing of the resource re^¬ lease was not successful.

In another embodiment illustrated in the message flow diagram of Figure 7, a new NBAP Class 1 procedure is introduced independently from the existing procedure in 3GPP.

At the first Common E-DCH resource configuration, the RNC 3 includes a new information element (IE) in the relevant IE Group in the message sent from the RNC 3 to the Node B 2. This new information element is shown in the last row of Table III. The new informa^¬ tion element IE requests the Node B 2 to use the new Class 1 procedure for E-RNTI release if the new Class 1 procedure is supported by the Node B 2.

Table III

Command

If the Node B 2 supports the new Class 1 procedure, the Node B 2 includes a new information element in the relevant IE Group in a message sent from the Node B 2 to the RNC 3, shown in the last row of Table IV. The

new IE informs the RNC 3 that the Node B 2 accepts to

use the new Class 1 procedure.

Table IV

IE for a UE

UE Status Update Confirm O BOOLEAN TRUE means that YES ignore Support Indicator NodeB support UE

Status Update

Confirm

After Common E-DCH operation is started, the Node B 2

receives the new Class 1: initiating message from the

RNC 3 containing a list of E-RNTIs for which the allo^¬ cated resource is released.

After successful processing of the initiating message;

i.e., if the Node B 2 has successfully released the

resource associate with each of the E-RNTIs on the

list, the Node B 2 sends a new class 1 response mes^¬ sage to the RNC. In the event that the Node B 2 does not successfully release the resource, the Node B 2 sends a new class 1 failure message to the RNC 3 instead of the Class 1 response message. In other words, the Class 1 proce^¬ dure involves explicitly sending a signalling message indicating success or failure of the resource release to the RNC 3.

This enables the Node B 2 to inform the RNC 3 of the result of successful operation for a received UE STATUS COMMAND message; i.e., a request from the RNC 3 for releasing the Common E-DCH resource for indicated E-RNTIs .

Although the invention has been described hereinabove with reference to specific embodiments, it is not lim^¬ ited to these embodiments and no doubt further alter^¬ natives will occur to the skilled person that lie within the scope of the invention as claimed.

For example, the communications network described above in the exemplary embodiments is a UMTS network, particularly a HSDPA (WCDMA) network. However, the invention may be applied in any other type of wireless communications network.

LIST OF ABBREVIATIONS

DCH Dedicated Channel

E-DCH Enhanced DCH

E-RNTI E-DCH Radio Network Temporary Identifier

HSDPA High Speed Downlink Packet Access

HSUPA High Speed Uplink Packet Access

NBAP Node B Application Protocol

RNC Radio Network Controller

SSCF Service Specific Coordination Function

User Network Interface

SSCOP Service Specific Connection Oriented Proto^¬ col

UE User Equipment

Claims

1. A method of managing resources in a communica^¬ tions network, the method comprising:

sending a resource release request from a control node;

receiving the resource release request at a network node; and

processing a resource release at the net^¬ work node based on the resource release request.

2. The method according to claim 1, wherein the step of processing comprises releasing or not releas^¬ ing a resource indicated in the resource release re^¬ quest .

3. The method according to claim 1 or claim 2, further comprising reporting an outcome of processing to the control node.

4. The method according to claim 3, wherein the step of reporting comprises sending an acknowledgement related to the request if the resource is released.

5. The method according to claim 3, wherein the step of reporting comprises sending a failure message related to the request if the resource is not released.

6. The method according to any of claims 1 to 5, further comprising performing a processing operation at the control node based an outcome of the processing of the resource release in the network node.

7. The method according to claim 6, wherein performing a processing operation comprises completing a resource release procedure in the control node if the resource was released during the step of processing in the network node.

8. The method according to claim 6, wherein performing a processing operation comprises repeating sending the resource release request from the control node if the resource was not released during the step of processing in the network node.

9. A method of managing resources in a communica^¬ tions network, the method comprising:

receiving a resource release request; and processing a resource release based on the resource release request.

10. The method according to claim 9, wherein the step of processing comprises releasing or not releas^¬ ing a resource indicated in the resource release re^¬ quest .

11. The method according to claim 9 or claim 10, further comprising reporting an outcome of processing of the resource release.

12. The method according to claim 11, wherein the step of reporting comprises sending an acknowledgement related to the request if the resource is released.

13. The method according to claim 11, wherein the step of reporting comprises sending a failure message related to the request if the resource is not released.

14. A method of managing resources in a communica^¬ tions network, the method comprising: sending a resource release request; and performing a processing operation depending on an outcome of processing of the resource release.

15. The method according to claim 14, wherein performing a processing operation comprises completing a resource release procedure if the outcome of process^¬ ing is that the resource was released in response to the resource release request.

16. The method according to claim 14, wherein performing a processing operation comprises repeating sending the resource release request if the outcome of processing is that the resource was not released in response to the resource release request.

17. The method according to any of claims 14 to 16, further comprising receiving a report of an outcome of processing of a resource release based on the resource release request.

18. A network node, comprising:

a receiver configured to receive a resource release request; and

a processor configured to process a resource release based on the resource release request.

19. The network node according to claim 18, wherein the processor is configured to release a resource or not release the resource based on the resource release request received at the receiver.

20. The network node according to claim 18 or claim 19, further comprising a transmitter configured to send a message reporting an outcome of processing of the resource release.

21. The network node according to claim 20, wherein the message sent by the transmitter contains an ac^¬ knowledgement related to the request if the resource is released by the processor.

22. The network node according to claim 20, wherein the message sent by the transmitter is a failure mes^¬ sage related to the request if the resource is not re^¬ leased by the processor.

23. A control node, comprising:

a transmitter configured to send a resource release request; and

a processor configured to perform a proc^¬ essing operation depending on the outcome of the processing of the resource release.

24. The control node according to claim 23, wherein the processing operation performed by the processor comprises completing a resource release procedure if the resource was released in response to the resource release request.

25. The control node according to claim 23, wherein the processing operation performed by the processor comprises repeating sending the resource release re^¬ quest if the resource was not released in response to the resource release request.

26. A communications network, comprising:

a control node configured to send a re^¬ source release request; and a network node configured to receive the resource release request from the control node, and to process a resource release based on the resource re^¬ lease request.

27. The communications network according to claim 26, wherein the network node is further configured to re^¬ port an outcome of processing to the control node.