HK1148154B - Transmission of the aggregate maximum bit rate from the mme to the e-node b and mobile terminal - Google Patents

Description

Transmission of aggregated maximum bit rate from MME to E-node B and mobile terminal

Technical Field

The present invention relates to an apparatus and method for signaling communications in a packet data network, such as a third generation partnership project (3GPP) cellular communication system.

Background

Third generation cellular communication systems are currently being initiated to further enhance the communication services provided to mobile phone users. The most widely deployed third generation communication systems are based on Code Division Multiple Access (CDMA) and Frequency Division Duplex (FDD) or Time Division Duplex (TDD) technologies. Further description of CDMA, and in particular, the Wideband CDMA (WCDMA) mode of UMTS, can be found in "WCDMA forUMTS", Harri Holma (editor), Antti Toskala (editor), Wiley & Sons, 2001, ISBN 0471486876.

In 3GPP systems such as General Packet Radio System (GPRS), Evolved Packet System (EPS), downlink communication endpoints, i.e. mobile or handheld wireless communication units (referred to as User Equipment (UE) in 3G parlance) may have multiple simultaneous connections with many network elements. Such network elements typically include Gateways (GWs), such as General GPRS Support Nodes (GGSNs), Packet Data Network (PDN) GWs, etc., to access different Packet Data Networks (PDNs) that facilitate UE access to many different services (e.g., facilitate access to corporate services, and access to the internet at the same time).

In such systems, the amount of data transferred between elements may be controlled by setting an Aggregate Maximum Bit Rate (AMBR), which is defined as an upper bound of a non-Guaranteed Bit Rate (GBR) communication bearer associated with a particular PDN connection that the UE has established.

In order to limit the amount of data transmitted to a corresponding PDN using AMBR, AMBR needs to be enforced for each non-Guaranteed Bit Rate (GBR) bearer connecting a UE and a particular GW providing access to a particular PDN.

In 3GPP (see, e.g., 3GPP TS23.401, "GPRS enhancements for E-UTRAN access", release 8), AMBR is enforced for Uplink (UL) traffic in node B110 in 3GPP, and AMBR is enforced for corresponding Downlink (DL) traffic in GW (e.g., in PDN-1 and PDN-2 GWs in 3 GPP). It is a natural choice that a given node B and GW are traffic portals for UL and DL traffic, respectively. Furthermore, since radio resources are the most cost sensitive for wireless operators, it is not reasonable to "pass" UL traffic over the air interface when it is to be discarded later.

Therefore, node B110 must be informed of the PDN connection that UE105 establishes at any time, and node B110 must be in a position to associate the radio bearer it gives scheduling priority with the UE-PDN connection it belongs to. In other words, for the UL scheduling decision it makes (e.g., by allocation of a prioritized bit rate PBR), the node B110 must consider the AMBR value and its relationship to each UE-PDN connection. Node B110 also controls radio bearer establishment and management. The node B110 establishes radio bearers for all corresponding Gateways (GWs) according to information received from an associated Core Network (CN)115 element, e.g., MME 120 in a 3GPP Evolved Packet System (EPS).

The characteristics of AMBR are somewhat different from other dynamic bearer parameters used to support a particular end-to-end QoS in wireless and other communication systems in the following sense:

(i) the AMBR value is applied to a "bundle" of non-GBR bearers for a particular UE-PDN connection, rather than to each non-GBR bearer individually. Thus, especially when the network element (e.g. node B) responsible for enforcing and supervising the AMBR is responsible for scheduling dynamically changing resources, the AMBR value requires special handling by this network element; and

(ii) the AMBR value is static subscriber information that is maintained in a subscriber database registry. Thus, as part of bearer establishment, the AMBR value must be communicated during the initial connection, rather than being dynamically provided by the policy server, as opposed to the manner in which other dynamically changing QoS parameters are typically provided.

Fig. 2 illustrates a known radio bearer establishment mechanism between the UE105 and the node B110, and AMBR policing in UL and DL, respectively. Notably, upon establishment of the radio bearer 205, a one-to-one relationship between the radio bearer 205 connecting the UE105 with the node B110 and the access bearer 210 terminating the traffic at the PDN GW 130 is maintained. At a given time, there may be more than one radio bearer 205 and access bearer 210 established for the UE105 to provide different quality of service (QoS) treatments to different user applications or different classes of users. In DL, the logical element of the scheduler in the node B110 schedules DL traffic according to the particular quality of service (QoS) of the radio bearer 205 that it has indicated with a certain QoS identifier during bearer establishment, and the amount of traffic used in the corresponding radio bearer 205. The AMBR policing of DL traffic is done at the respective PDN GW 130, 135, 140, 145, where a given 3GPP Policy and Charging Enforcement Function (PCEF) is typically located, since the PDN GW 130, 140 is the first entry point for Downlink (DL) traffic.

If the AMBR level is exceeded for a particular PDN connection in the DL, the 3GPP PCEF in the PDNGW can rate limit the excess traffic from all access (non-GBR) bearers 210 of that PDN GW to comply with the provisioned AMBR transmitted to the PDN GW at the initial bearer establishment.

Thus, UL resources are allocated by the appropriate logic element of the scheduler in node B110 according to the traffic volume reported by the UE and are allocated on a per UE basis. The scheduling of the radio bearer 205 to the assigned grant is performed by the UE105 using the logical function of the UL packet scheduler according to the priority communicated to it by the node B110 when establishing the radio bearer. In order to control radio bearer scheduling of the UE105, an UL rate control function that manages sharing of UL resources between radio bearers is specified in 3 GPP. The scheduler in node B110 configures each radio bearer 205 with scheduling parameters, such as absolute priority values and Priority Bit Rate (PBR) values, according to quality of service (QoS) parameters, such as QoS labels and GBR values, of the GBR bearers, communicated by the Core Network (CN). Further, optionally, the Maximum Bit Rate (MBR) may be configured per radio bearer 205. The assigned priority values and PBRs are signaled to the UE105 along with the radio bearer configuration information. The priority value is decided by the node B110 according to QoS information received from the Core Network (CN) 115. In this way, PBR sets the UL rate control limit applied per radio bearer at the UE and ensures that the UE105 serves its radio bearers 205 in descending priority order up to the PBR value of its radio bearers 205.

All radio bearers 205 are served in a strictly decreasing priority order up to the MBR of the radio bearer 205 (if configured) if any resources are still available. Without the MBR being configured, the radio bearer 205 is served until either the data or UL grant for that radio bearer 205 is exhausted, whichever occurs first. Generally, these parameters are scheduling priority parameters applied in the case of a 3GPP Long Term Evolution (LTE) wireless communication system.

However, the inventors have found and appreciated that the allocation of these scheduling parameters (e.g. PBR, priority and MBR (optional) in the case of a 3GPP LTE wireless communication system) is independent of the AMBR applied to the entire UE-PDN connection served by the radio bearer. In practice, this means that if two bearers have the same QoS characteristics (e.g. QoS labels), even if they belong to two different PDN connections (e.g. one with a high AMBR value and one with a low AMBR value), the two radio bearers will be subjected to the same scheduling process given that the AMBR is not communicated to the node B. Thus, this situation is inefficient and wastes valuable resources. For example, if one bearer serves hypertext transfer protocol (HTTP) traffic from a Virtual Private Network (VPN) with a high AMBR and HTTP traffic from the internet with a low AMBR, the same scheduling process at node B110 and UE105 would apply for both.

Thus, current techniques are not optimal. Thus, an improved mechanism to address the problem of handling AMBR over cellular networks would be advantageous.

Disclosure of Invention

Accordingly, the invention seeks to mitigate, alleviate or eliminate one or more of the above mentioned disadvantages singly or in any combination.

According to a first aspect of the present invention, there is provided a method of signalling in a wireless communication system comprising a first network element providing at least one Packet Data Network (PDN) connection to a wireless communication unit. The method comprises the following steps: the first network element sends a signaling message to the wireless communication unit related to a wireless communication unit Uplink (UL) PDN transmission. The signaling message includes a parameter indicating at least one Aggregated Maximum Bit Rate (AMBR) value.

In this way, a mechanism is provided for policing AMBR values in a node B without unnecessarily wasting uplink resources by modifying, for example, a scheduler function in the node B to allocate scheduling parameters related to the value of the ul AMBR that has to be enforced for the radio bearers served over the UE-PDN connection.

Thus, embodiments of the present invention allow for improved use of communication resources by more efficiently utilizing uplink resources in a communication system, e.g., because the node B does not admit Uplink (UL) traffic transmitted by the UE, which has to be discarded later if the traffic exceeds the AMBR value. Thus, the present invention may provide increased throughput and increase the capacity of a communication system by not admitting traffic that may then have to be dropped. Furthermore, the invention may allow improved performance as perceived by the end user and may also allow the network operator to increase the number of users that the system can support, while still being able to control the ul ambr transmitted by the UE to a certain PDN connection.

According to an optional feature of the invention, the sending referred to above comprises sending as part of the establishment of the at least one PDN connection. In this way, the signaling message may be implemented within an existing message that establishes at least one PDN connection.

According to an optional feature of the invention, the signalling message comprises at least one AMBR value. In this way, the need for disassociation of the parameters generated by the network element from the directly provided AMBR values can be avoided.

According to an optional feature of the invention, the signalling message comprises a parameter associated with at least one AMBR value. In this way, existing signalling parameters may be modified to reflect (be associated with) at least one AMBR value.

According to an optional feature of the invention, the method further comprises: the first network element associates data packets received from the wireless communication unit with a user transmission priority associated with at least one PDN connection in accordance with the at least one AMBR value. In this manner, a user transmission priority may be associated with at least one PDN connection to reflect at least one AMBR value (associated with at least one AMBR value).

According to an optional feature of the invention, the at least one PDN identifier of each PND connection may be associated in dependence on the at least one AMBR value.

According to an optional feature of the invention, the method further comprises: the first network element derives a Maximum Bit Rate (MBR) value for each PDN connection of the wireless communication unit to the first network element, based on the at least one AMBR value.

In accordance with an optional feature of the invention, the wireless communication system further comprises a first network element operatively coupled to the second network element via a PDN connection. The method further comprises: sending, by the second network element, a signaling message to the first network element relating to a wireless communication unit ULPDN transmission. In this way, an element in the core network, such as a Mobility Management Entity (MME), may be configured to access and communicate AMBR values via, for example, a user profile of the wireless communication unit containing at least one AMBR value per PDN connection.

According to an optional feature of the invention, the method further comprises: the first network element identifies when an allocation of user transmission priority values exceeds an AMBR value applied to at least one PDN connection.

According to an optional feature of the invention, the method further comprises: the first network element reallocates at least one user transmission priority value associated with at least one PDN connection when an AMBR value is exceeded.

According to an optional feature of the invention, the step of transmitting referred to above comprises: the transmission is made as part of an attach procedure to establish at least one PDN connection of the wireless communication unit to the first network element. In this manner, signaling messages may be implemented within existing messages that establish at least one PDN connection.

In an alternative embodiment, the at least one PDN connection of the wireless communication unit includes multiple PDN connections accessed by the wireless communication unit, e.g., the attach procedure may establish multiple PDN connections accessed by the wireless communication unit.

In an alternative embodiment, the method is applicable to a third generation partnership project (3GPP) cellular communication system. In an alternative embodiment, the method may be applied to a 3GPP Evolved Packet System (EPS) architecture.

In an alternative embodiment, the method may be applied to a WiMAX cellular communication system.

According to a second aspect of the present invention, there is provided a network element configured to provide signalling in a wireless communication system to a wireless communication unit over at least one Packet Data Network (PDN) connection. The network element includes logic to transmit a signaling message related to a wireless communication unit Uplink (UL) PDN transmission to the wireless communication unit, wherein the signaling message includes a parameter indicating at least one Aggregated Maximum Bit Rate (AMBR) value.

According to a third aspect of the present invention, there is provided a wireless communication unit configured to receive a signaling message in a wireless communication system from a network element over at least one Packet Data Network (PDN) connection. The wireless communication unit includes logic to receive a signaling message related to an Uplink (UL) PDN transmission of the wireless communication unit, wherein the signaling message includes a parameter indicating at least one Aggregated Maximum Bit Rate (AMBR) value.

According to a fourth aspect of the present invention, there is provided a method of signalling in a wireless communication system comprising a first network element providing at least one Packet Data Network (PDN) connection to a wireless communication unit. The method includes a wireless communication unit receiving, from a first network element, a signaling message related to an Uplink (UL) PDN transmission from the wireless communication unit, wherein the signaling message includes a parameter indicating at least one Aggregated Maximum Bit Rate (AMBR) value.

According to a fifth aspect of the present invention, there is provided a computer program product comprising program code for signalling transmissions from a network element to a wireless communication unit over at least one Packet Data Network (PDN) connection in a wireless communication system. The computer program product includes program code to transmit a signaling message related to a wireless communication unit Uplink (UL) PDN transmission to the wireless communication unit, wherein the signaling message includes a parameter indicating at least one Aggregated Maximum Bit Rate (AMBR) value.

These and other aspects, features and advantages of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter.

Drawings

Fig. 1 illustrates a known 3GPP system using AMBR.

Fig. 2 illustrates known AMBR policing occurring in a node B for UL traffic and in a GW for DL traffic.

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

fig. 3 illustrates a system architecture suitable for use in some embodiments.

Fig. 4 illustrates an attach procedure and bearer establishment, in accordance with some embodiments.

Fig. 5 illustrates an attach procedure and bearer establishment for an EPS/LTE system, in accordance with some embodiments.

Fig. 6 illustrates a scheduling mechanism for a set of bearers corresponding to the same UE-PDN connection, in accordance with some embodiments.

FIG. 7 illustrates a typical computing system that may be used to implement processing functionality in embodiments of the invention.

Detailed Description

The following description is directed to embodiments of the present invention applicable to an Evolved Packet System (EPS) Core Network (CN) architecture within an evolved UMTS (universal mobile telecommunications system) cellular communication system, and in particular a third generation partnership project (3GPP) system. It will be appreciated, however, that the invention is not limited to this particular cellular communication system, but is applicable to other cellular communication systems.

Embodiments of the present invention propose to obtain AMBR parameters and their associated PDN connection identifiers from a static subscriber database when a communication endpoint initially boots up and attaches in the network. Furthermore and advantageously, the AMBR together with its associated PDN connection identifier is transmitted to the network element responsible for policing and enforcing the AMBR per PDN connection.

Additionally, some embodiments propose a network element that enforces AMBR for multiple PDN connections where a communication endpoint (e.g., UE) may already be in place. Thus, the network element is configured to be responsible for serving multiple communication endpoints in an environment where resources dynamically change.

Referring now to fig. 3, a wireless communication system 300 is schematically illustrated, in accordance with one embodiment of the present invention. In the present embodiment, the wireless communication system 300 is compliant with a Universal Mobile Telecommunications System (UMTS) air interface and includes network elements capable of operating over a Universal Mobile Telecommunications System (UMTS) air interface. In particular, the present embodiments relate to the system architecture of an evolved-UTRAN (E-UTRAN) wireless communication system currently under discussion in 3 GPP. This is also known as Long Term Evolution (LTE).

The architecture consists of Radio Access Network (RAN) elements and Core Network (CN) elements, where a core network 304 is coupled to an external network 302, such as the internet or a corporate network, named Packet Data Network (PDN). The main components of the RAN are enode bs (evolved node bs) 310, 320 connected to the CN 304 via an S1 interface and to the UE 320 via a Uu interface. The enode bs 310, 320 control and manage functions related to radio resources. A series of node bs 310, 320 typically perform lower layer processing for the network, such as Medium Access Control (MAC), formatting data blocks for transmission, and physically transmitting transport blocks to the UE 325. In addition to these functions normally performed by the node B, the adapted node B310 scheduler logic element is further configured to interact with the logic elements of the PEF, which are designated as non-GBR bearers belonging to a certain UE-PDN connection to enforce UL AMBR in order to provide a subset of the functions implemented in the Downlink (DL) by the 3gpp ppcef located in the PDN GW305, such as rate limiting. An additional limitation is that the rate limiting function of the PEF logic element in the UL must meet certain performance and it cannot simply "pass" traffic over the air and then drop it. Thus, the adaptation scheduler in the node B310 is configured to derive appropriate scheduling parameters to be transmitted to the UE 320 in order to support this operation, according to the AMBR that has to be enforced by the logic element of the Policy Enforcement Function (PEF) located in the node B310.

CN 304 has three main components: a serving GW306, a PDN GW (PGW)305, and a Mobility Management Entity (MME) 308. The serving GW306 controls U-plane (user plane) communications. The PDN-GW 305 controls access to an appropriate external network (e.g., PDN). In addition to this operation, in one embodiment, the PDN-GW 305 is configured to supervise the dl ambr of many non-GBR bearers serving this particular UE-PDN connection. MME 308 controls c-plane (control plane) communications, where user mobility, paging initiation for idle mode UEs, bearer establishment, and QoS support for default bearers are handled by MME 308. In addition to these operations, in one embodiment, MME 308 is configured to obtain the UL and DL AMBR values applied to each PDN connection that UE 320 is allowed to establish, typically using a database query mechanism to Home Subscriber Server (HSS)330 through a protocol such as DIAMETER (as in RFC 3588) or RADIUS (as in RFC 2865). The UL and DL AMBR values are based on the subscription profile and provisioning information of the UE, which may be held in a static database such as the HSS 330 that may contain user credentials for UE authentication, user classes in terms of service classes, and other static information. The UL AMBR value is transmitted to a logical element of the PEF in the node B310 designated to enforce UL AMBR, and the DL AMBR value is transmitted to the 3GPP PCEF in the PDN GW305 to which the UE 320 is originally attached.

The E-UTRAN RAN is based on OFDMA (orthogonal frequency division multiple Access) in the Downlink (DL) and SC-FDMA (Single Carrier frequency division multiple Access) in the Uplink (UL). Further information on the radio frame format and physical layer configuration used in E-UTRAN can be found in TS36.211(3GPP TS36.211 v.1.1.1(2007-05), "3 GPP technical discovery group radio access network, physical channels and modulation (release 8)".

The node B310 is wirelessly connected with the UE 325. Each node B includes one or more transceiver units 312, 322 operatively coupled to respective signal processing logic 314, 324. Similarly, each UE includes a transceiver unit 327 (only one UE is illustrated in such detail for clarity) operably coupled with signal processing logic 329, and communicates with node bs supporting communication in their respective location areas. The system contains many other UEs and node bs which are not shown for clarity.

Signaling of AMBR values

According to one embodiment of the invention, the interaction between the UE325, the node B310, the MME 308, the GW305, 306 and the AAA has been adapted to support an improved use of AMBR signaling. In particular, the AMBR value of each UE-PDN connection and the PDN gateway identifier from the CN to the radio access network are transmitted to appropriately transmit the available PDN connections where the UE is already in place. This mechanism is described in more detail below with reference to fig. 4.

Referring now to fig. 4, a single signaling flow diagram illustrating two possibilities for end-to-end bearer establishment in a wireless communication system is illustrated:

(i) UE-initiated; and

(ii) network initiated.

It is noted that the signaling exchange may also include many other messages and other information not relevant to the description of the embodiments described herein.

In step 430, the UE325 initiates an attach procedure by, for example, sending its temporary identity (e.g., UE System Architecture Evolution (SAE) -temporary Mobile subscriber identity (S-TMSI) or packet-temporary Mobile subscriber identity (P-TMSI)) to the node-B310. In the case of UE-initiated bearer establishment, the Access Point Name (APN) will indicate the appropriate gateway 420 serving the PDN to which the UE325 wishes to connect.

In the case of network-initiated bearer establishment, the UE325 need not provide any indication, as the MME 308 will establish connections to all PDNs that the UE325 is allowed to access according to its subscription profile.

In step 435, the node B310 gets the appropriate MME 308 to which it has to forward the attach request based on the temporary identity of the UE325, e.g., the UES-TMSI or P-TMSI. In steps 440, 445, the MME 308 completes the authentication procedure with the UE 325.

In step 450, MME 308 obtains subscriber information for UE325, including information about all PDNs that UE325 accesses. At this stage, MME 308 will have to be able to build a table for UE325, e.g., a table as illustrated in table 1 below.

TABLE 1

In step 455, the MME 308 creates and sends a bearer request (or requests a bearer based on whether it is a UE-initiated setup or a network-initiated setup) to create a connection to the GW305, 306.

In case of UE initiated setup, given that the UE325 has indicated in step 430 a unique GW address to which it wishes to connect through the APN, the MME 308 will only send a bearer request to that GW305, 306. The bearer request contains the DL AMBR that the GW305, 306 must enforce for the connection.

In the case of network-initiated bearer establishment, MME 308 sends a bearer request to all GWs serving the PDN that UE325 accesses (as identified, for example, by the list of APNs that MME 308 obtained in step 450). In one embodiment, the request contains the DL AMBR for each APN that the relevant GW must enforce.

In step 460, the GW305, 306 creates and sends a bearer response. In case of UE initiated bearer establishment, only the selected GW305, 306 receiving the bearer request sends a bearer response.

In step 465, MME 308 sends an attach response to node B310, the attach response containing QoS information and a value of UL AMBR. In case of UE initiated setup, the attach response message will only contain the information needed for the specific UE PDN connection. In case of network initiated setup, the attach response message contains all information about the UL AMBR and QoS of all APNs accessed by the UE.

In step 470, the node B310 establishes the relevant radio bearer according to the information provided in step 465. In case of UE initiated establishment, this results in only one radio bearer being established corresponding to the particular UE-PDN connection. In the case of network-initiated establishment, at this stage node B310 establishes all radio bearers serving all required PDN connections for the UE.

The mechanism by which the node B310 processes the information provided in step 465 to determine the scheduling parameters is as follows.

Referring now to fig. 5, an enhanced embodiment is described with respect to AMBR signaling in the core network of E-UTRAN. As defined in 3GPP TS23.401, "GPRS enhancement for e-UTRAN access", release 8, the AMBR associated with each PDN that the UE 405 accesses is kept in a Home Subscriber Server (HSS) based on subscriber information (equivalent to the home location register in earlier GSM based systems). As part of the "attach" procedure illustrated in steps 430, 435 of fig. 4, the AMBR is retrieved by the MME 415.

For example, as illustrated in table 2 below, the following information may be saved in the HSS for each UE:

TABLE 2

After UE attach, this information is retrieved in MME 415 and should be provided in PDN GW422 and enodeb 410 for DL and UL supervision, respectively.

In this regard, as shown in step 550, the DL value of the AMBR may be sent from the MME 415 to the PDN GW422 as part of the "create default bearer message" so that the PDN GW422 can supervise the AMBR in the DL. In this regard, it is also contemplated that the UL AMBR may also be sent from the MME 415 to the enodeb 410 as part of an attach accept message, as illustrated in step 555.

Thus, the following additional signaling is proposed for the EPS/LTE attach procedure described in 3GPP TS23.401, "GPRS enhancements for e-UTRAN access", release 8, to enable the above mentioned communication.

In step 515, HSS 510 sends an insert subscriber data message (e.g., IMSI, subscription data) to new MME 412. The subscription data contains the default APN, and UL and DL AMBR values for APNs accessed by the UE 405. The new MME 412 verifies the presence of the UE in the (new) tracking area/location area (TA/LA). If the UE 405 is not allowed to attach in the TA/LA due to area subscription restrictions or access restrictions, the new MME 412 can reject the attach request in step 435 for the appropriate reason and may return an "insert user data confirm" message 520 to the HSS 510. If the subscription check fails for other reasons, the new MME 412 may reject the attach request 430, 435 for the appropriate reason and return an insert user data confirm message to the HSS including the error reason. If all checks are successful, the new MME 412 builds a context for the UE 405 and returns an insert user data acknowledgement message 520 to the HSS 510. As shown in step 525, the HSS may send an update location acknowledgement message to the new MME 412 according to the existing procedures described in 3GPP TS23.401, "GPRS enhancements for E-UTRAN access," release 8, section 5.3.2.

In step 530, the new MME 412 selects the serving GW 420 as described under "GW selection function" in the above mentioned standard and sends a create default bearer request (IMSI, MME context ID, default bearer QoS, DL AMBR of default APN) to the selected serving GW 420.

In step 535, the serving GW 420 creates a new entry in its EPS bearer table and sends a create default bearer request (serving GW address of user plane, serving GW TEID of control plane, default bearer QoS, DL AMBR of default APN) to the PDN GW 422.

At step 540, if a Policy and Charging Rules Function (PCRF) is applied in the network, the PDN GW422 may interact with the Policy and Charging Rules Function (PCRF)505 to obtain default Policy Control and Charging (PCC) Rules for the UE 405. The PDN GW422 then saves the DL AMBR for the UE 405 for the default bearer.

The subsequent messages 545 and 550 are sent according to the existing procedure described in section 5.3.2 of 3GPP TS23.401, "GPRS enhancements for E-utran access", release 8.

In step 555, the new MME 412 sends an "attach accept" (including S-TMSI, PDN address, TA/LA list) message to the enodeb 410. If the new MME allocates a new S-TMSI, then the S-TMSI is included. This message may be contained in the S1_ MME control message: in the initial context setup request. The S1 control message may also include security context and QoS information of the UE 405 required to establish the radio bearer, as well as a Terminal Entity Identifier (TEID) at the serving GW 420 for the user plane, and an address of the serving GW 420 for the user plane.

The PDN address allocated to the UE 405 is included in the message. The APN of the PDN GW422 to which the UE 405 is connected may also be included in this message. The new MME 412 sends the ULAMBR to the enodeb 410.

In step 560, the enodeb 410 sends a radio bearer setup request to the UE 405 and an attach accept message (S-TMSI, PDN address, TA list, APN)555 will be sent together to the UE 405.

Thereafter, messages 565 and 590 are sent as described in 3GPP TS23.401, "GPRS enhancements for E-UTRAN Access", release 8, section 5.3.2.

AMBR handling in a radio access network, e.g. a node B

The interaction between the UE325, the node B310, the MME 308, the GW305, 306, and the AAA is further adapted to support an improved use of AMBR information signaled between the elements, according to an embodiment of the present invention. In particular, an apparatus and method are proposed that allow a Radio Access Network (RAN) to prioritize traffic belonging to a particular PDN connection according to AMBR, taking into account information provided from a Core Network (CN). In an enhanced embodiment, an apparatus and method for enforcing AMBR in node B310 is also presented. The proposed mechanism configures the scheduler in the node B310 to allocate appropriate scheduling priority parameter values (e.g. PBR, priority values, MBR in 3GPP) to the radio bearers in addition to the transmitted QoS information to reflect the mandatory execution of UL AMBR applied to the entire set of radio bearers corresponding to the UE-PDN connection that the PEF has to perform. Furthermore, a mechanism is proposed to optimize the signaling (reduced signaling overhead) between the node B410 and the UE 405 to specify and modify the scheduling priorities as needed in order to supervise the AMBR applied to the UE-PDN connection.

In case the UE 405 has multiple PDN connections, the PEF logic in the node B410 needs to supervise the UL traffic belonging to each PDN connection separately. Thus, the PEF logic in the node B410 should be informed of any association between the access bearer and the PDN connection during bearer establishment.

In step 470 of fig. 4, the simplified traffic policing case is the case where UL traffic exceeds the AMBR value for a particular PDN connection, in which case the data may be discarded at node B410. However, the data has been sent over the air interface. Therefore, discarding the transmitted data at the node B410 will result in inefficient use of radio resources.

Although embodiments of the present invention have been described with reference to an MME that obtains at least one Aggregate Maximum Bit Rate (AMBR) value and communicates it to the PEF logic of a node B, in alternative embodiments it is envisaged that the PEF logic of a node B may directly obtain the UL AMBR value. In this case, the node B is configured to have a direct interface to an AAA server (or Home Subscriber Server (HSS) in case of a 3GPP system), and performs mobility management, user authentication, and QoS provisioning of default bearer functions by itself. In other words, in this case, all current functions of the MME are contained in the node B.

Furthermore, although embodiments of the present invention have been described with reference to an MME obtaining and transmitting at least one Aggregate Maximum Bit Rate (AMBR) value to a node B, wherein the node B generates an association of the AMBR with at least one PDN identifier, in alternative embodiments it is envisaged that the node B is capable of obtaining the AMBR value and sending the AMBR value directly to a wireless communication unit (e.g. a UE). In this case, the UE will be responsible for the supervision of UL AMBR of many radio bearers belonging to a particular UE-PDN connection. In addition to the AMBR, in this case, the node B may transmit information of the PDN identifier to the UE at radio bearer setup. However, the inventors have recognized that there are limitations to this situation as follows: the supervision of the AMBR associated with the management of radio resources will be communicated solely to UEs traditionally considered "untrusted" entities in similar communication systems.

AMBR handling in a node B based on absolute priority allocation per PDN connection

Referring now to fig. 6, one possible mechanism for scheduling in a node B is illustrated. The mechanism is based on AMBR values that have been transmitted as part of bearer establishment, during radio bearer configuration, an Identifier (ID) of the PDN GW422 or 424 (e.g., APN in 3GPP) is signaled to the UE 405 along with assigned scheduling priority parameters (e.g., absolute priority value and PBR in 3 GPP). In addition to this signaling, absolute priority is signaled to apply to a set of bearers related to a particular PDN connection. For example, the priority applied to each radio bearer may be defined in two steps. First, each PDN connection is provided with an absolute priority value (P)_i 505、P_z510). Second, the priority of the radio bearer is given a relative value with respect to the absolute priority value of the PDN connection. Thus, the UE 405 may calculate the absolute priority value of the radio bearer by considering the absolute priority value of the PDN connection and the relative priority value of the radio bearer.

It will be appreciated that for clarity, the above description has described embodiments of the invention with reference to different functional units and processors. However, it will be apparent that any suitable distribution of functionality between different functional units or processors (e.g., with respect to broadcast mode logic or management logic) may be used without detracting from the invention. For example, functionality illustrated to be performed by separate processors or controllers may be performed by the same processor or controller. Thus, references to specific functional units are only to be seen as references to suitable means for providing the described functionality rather than indicative of a strict logical or physical structure or organization.

Aspects of the invention may be implemented in any suitable form including hardware, software, firmware or any combination of these. Alternatively, the invention may be implemented at least partly as computer software running on one or more data processors and/or digital signal processors. Thus, the elements and components of an embodiment of the invention may be physically, functionally and logically implemented in any suitable way. Indeed the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units.

FIG. 7 illustrates a typical computing system 700 that may be used to implement processing functionality in embodiments of the invention. Such a computing system may be used in a UE (which may be an integrated device such as a mobile phone or a USB/PCMCIA modem), or a node B (in particular, the scheduler of the node B), a core network element such as a GGSN and an RNC. Those skilled in the relevant art will also recognize how to implement the invention using other computer systems or architectures. Computing system 700 may represent, for example, a desktop, laptop or notebook computer, hand-held computing device (PDA, cell phone, palmtop, etc.), mainframe, server, client, or any other type of special or general purpose computing device as may be desired or appropriate for a given application or environment. Computing system 700 can include one or more processors, such as a processor 704. Processor 704 may be implemented using a general or special purpose processing engine such as, for example, a microprocessor, microcontroller or other control logic. In this example, processor 704 is connected to a bus 702 or other communication medium.

Computing system 700 can also include a main memory 708, such as Random Access Memory (RAM) or other dynamic memory, for storing information and instructions to be executed by processor 704. Main memory 708 also may be used for storing temporary variables or other intermediate information during execution of instructions to be executed by processor 704. Similarly, computing system 700 may include a Read Only Memory (ROM) or other static storage device coupled to bus 702 for storing static information and instructions for processor 704.

Computing system 700 may also include information storage system 710. information storage system 710 may include, for example, a media drive 712 and a removable memory interface 720. The media drive 712 may include a drive or other mechanism to support fixed or removable storage media, such as a hard disk drive, a floppy disk drive, a magnetic tape drive, an optical disk drive, a Compact Disc (CD) or Digital Video Drive (DVD) read or write drive (R or RW), or other removable or fixed media drive. Storage media 718 may include, for example, a hard disk, floppy disk, magnetic tape, optical disk, CD or DVD, or other fixed or removable medium that is read by and written to by media drive 714. As these examples illustrate, the storage media 718 may include a computer-readable storage medium having stored therein particular computer software or data.

In alternative embodiments, information storage system 710 may include other similar components for allowing computer programs or other instructions or data to be loaded into computing system 700. Such components may include, for example, a removable storage unit 722 and an interface 720, such as a program cartridge and cartridge interface, a removable memory (for example, a flash memory or other removable memory module) and memory slot, and other removable storage units 722 and interfaces 720 that allow software and data to be transferred from the removable storage unit 718 to computing system 700.

Computing system 700 may also include a communications interface 724. Communication interface 724 may be used to allow software and data to be transferred between computing system 700 and external devices. Examples of communication interface 724 include a modem, a network interface (such as an ethernet or other NIC card), a communication port (such as, for example, a Universal Serial Bus (USB) port), a PCMCIA slot and card, etc. Software and data transferred via communications interface 724 are in the form of signals which may be electrical, electromagnetic, optical, or other signals capable of being received by communications interface 724. These signals are provided to communications interface 724 via a path 728. The channel 728 may carry signals and may be implemented using a wireless medium, wire or cable, fiber optics, or other communications medium. Some examples of channels include telephone lines, cellular telephone links, RF links, network interfaces, local or wide area networks, and other communication channels.

In this document, the terms "computer program product," "computer-readable medium," and the like may be used generally to refer to media such as, for example, memory 708, storage 718, or storage unit 722. These and other forms of computer-readable media may store one or more instructions for use by processor 704, to cause the processor to perform specified operations. Such instructions, generally referred to as "computer program code" (which may be categorized in the form of computer programs or other groupings), when executed, enable the computing system 700 to perform functions of embodiments of the present invention. Note that the code may directly cause the processor to perform specified operations, be compiled to cause the processor to perform specified operations, and/or be combined with other software, hardware, and/or firmware elements (e.g., libraries that perform standard functions) to cause the processor to perform specified operations.

In an embodiment where the elements are implemented using software, the software may be stored in a computer-readable medium and loaded into computing system 700 using, for example, removable storage drive 714, drive 712 or communications interface 724. When executed by the processor 704, the control logic (in this example, software instructions or computer program code) causes the processor 704 to perform the functions of the invention as described herein.

It will be appreciated that for clarity, the above description has described embodiments of the invention with reference to different functional units and processors. However, it will be apparent that any suitable distribution of functionality between different functional units, processors or domains may be used without detracting from the invention. For example, functionality illustrated to be performed by separate processors or controllers may be performed by the same processor or controller. Thus, references to specific functional units are only to be seen as references to suitable means for providing the described functionality rather than indicative of a strict logical or physical structure or organization.

Aspects of the invention may be implemented in any suitable form including hardware, software, firmware or any combination of these. Alternatively, the invention may be implemented at least partly as computer software running on one or more data processors and/or digital signal processors. Thus, the elements and components of an embodiment of the invention may be physically, functionally and logically implemented in any suitable way. Indeed the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units.

Although the present invention has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the scope of the invention is limited only by the claims. In addition, while a feature may appear to be described in connection with particular embodiments, one skilled in the art would recognize that various features of the described embodiments may be combined in accordance with the invention.

Furthermore, although individually listed, a plurality of means, elements or method steps may be implemented by a single unit or processor. Furthermore, although individual features may be included in different claims, these may possibly advantageously be combined, and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. Also, the inclusion of a feature in one category of claims does not imply a limitation to this category, but rather the feature may be equally applicable to other claim categories, as appropriate.

Furthermore, the order of individual features in the claims does not imply any specific order in which the individual features must be performed and in particular the order of individual steps in a method claim does not imply that the individual steps must be performed in this order. But rather the steps may be performed in any suitable order. Furthermore, singular references do not exclude a plurality. Thus, references to "a", "an", "first", "second", etc., do not preclude a plurality.

Claims (13)

1. An apparatus for operating a mobile unit to communicate packet data between the mobile unit and a wireless communications network to support user services, the apparatus comprising:

means for establishing, in conjunction with the wireless communication network, one or more packet data network connections with one or more packet data networks, for providing one or more non-guaranteed bit rate bearers,

means for receiving from the wireless communication network an indication of an UL aggregated maximum bit rate for each of the one or more packet data network connections with the one or more packet data networks, and

means for transmitting packet data from the mobile unit to the wireless communication network via the non-guaranteed bit rate bearer in order to limit an aggregated bit rate of packet data transmitted via the non-guaranteed bit rate bearer based on the UL aggregated maximum bit rate,

wherein the wireless communication network comprises a plurality of base stations and a mobility management entity, and wherein the UL aggregated maximum bit rate is transmitted from the mobility management entity via a base station serving the mobile unit.

2. The apparatus of claim 1, wherein the wireless communication network comprises a home subscriber server including user information for a mobile unit, and the mobility management entity is configured to obtain the UL aggregate maximum bit rate from the home subscriber server for transmission to the mobile unit.

3. The apparatus of claim 1, wherein the indication of the UL aggregate maximum bitrate is received as a priority value for each of the plurality of non-guaranteed bitrate bearers and an UL aggregate maximum bitrate value with an identifier of a packet data network connection, and the apparatus further comprises:

means for scheduling transmission of data packets via the plurality of non-guaranteed bit rate bearers using the priority values.

4. The apparatus of claim 1, wherein the indication of the UL aggregate maximum bit rate is received as part of a configuration of radio bearers of the one or more non-guaranteed bit rate bearers.

5. The apparatus of claim 1, wherein the one or more non-guaranteed bit rate bearers are established as part of a mobile originated call.

6. The apparatus of claim 1, wherein the one or more non-guaranteed bit rate bearers are established as part of a call initiated by the mobile communication network.

7. The apparatus of claim 1, wherein the wireless communication network operates in accordance with a third generation partnership project 3GPP standard and the base station is a node B or an enodeb.

8. The apparatus of claim 7, wherein the wireless communication system operates in accordance with an Evolved Packet System (EPS) architecture.

9. A method of operating a mobile unit to communicate packet data between the mobile unit and a wireless communications network to support user services, the method comprising:

establishing, in conjunction with the wireless communication network, one or more packet data network connections with one or more packet data networks for providing one or more non-guaranteed bit rate bearers,

receiving, from the wireless communication network, an indication of an UL aggregated maximum bit rate for each of the one or more packet data network connections with the one or more packet data networks, and

transmitting packet data from the mobile unit to the wireless communication network via the non-guaranteed bit rate bearer to limit an aggregated bit rate of packet data transmitted via the non-guaranteed bit rate bearer based on the UL aggregated maximum bit rate,

wherein the wireless communication network comprises a plurality of base stations and a mobility management entity, and wherein the UL aggregated maximum bit rate is transmitted from the mobility management entity via a base station serving the mobile unit.

10. The method of claim 9, wherein the wireless communication network comprises a home subscriber server including user information for a mobile unit, and the mobility management entity is configured to obtain the UL aggregate maximum bit rate from the home subscriber server for transmission to the mobile unit.

11. The method of claim 9, wherein the indication of the UL aggregate maximum bitrate is received as a priority value for each of the plurality of non-guaranteed bitrate bearers and an UL aggregate maximum bitrate value with an identifier of a packet data network connection, and the method further comprises:

scheduling transmission of data packets via the plurality of non-guaranteed bit rate bearers using the priority values.

12. The method of claim 9, wherein the indication of the UL aggregate maximum bit rate is received as part of a configuration of radio bearers of the one or more non-guaranteed bit rate bearers.

13. The method of claim 9, wherein the wireless communication network operates in accordance with a third generation partnership project 3GPP standard and the base station is a node B or an enodeb.