METHOD. SYSTEM AND APPARATUS

FIELD

The present application relates to a method, apparatus, system and computer program and in particular but not exclusively, to LTE-WLAN interworking.

BACKGROUND

A communication system can be seen as a facility that enables

communication sessions between two or more entities such as user terminals, base stations and/or other nodes by providing carriers between the various entities involved in the communications path. A communication system can be provided for example by means of a communication network and one or more compatible communication devices. The communication sessions may comprise, for example, communication of data for carrying communications such as voice, electronic mail (email), text message, multimedia and/or content data and so on. Non-limiting examples of services provided comprise two-way or multi-way calls, data

communication or multimedia services and access to a data network system, such as the Internet.

In a wireless communication system at least a part of a communication session between at least two stations occurs over a wireless link. Examples of wireless systems comprise public land mobile networks (PLMN), satellite based communication systems and different wireless local networks, for example wireless local area networks (WLAN). The wireless systems can typically be divided into cells, and are therefore often referred to as cellular systems.

A user can access the communication system by means of an appropriate communication device or terminal. A communication device of a user is often referred to as user equipment (UE). A communication device is provided with an appropriate signal receiving and transmitting apparatus for enabling

communications, for example enabling access to a communication network or communications directly with other users. The communication device may access a carrier provided by a station, for example a base station of a cell, and transmit and/or receive communications on the carrier. The communication system and associated devices typically operate in accordance with a given standard or specification which sets out what the various entities associated with the system are permitted to do and how that should be achieved. Communication protocols and/or parameters which shall be used for the connection are also typically defined. An example of attempts to solve the problems associated with the increased demands for capacity is an architecture that is known as the long-term evolution (LTE) of the Universal Mobile Telecommunications

System (UMTS) radio-access technology. The LTE is being standardized by the 3rd Generation Partnership Project (3GPP). The various development stages of the 3GPP LTE specifications are referred to as releases.

SUMMARY

The present invention is defined by the appended independent claims. Further more specific aspects are defined by the appended dependent claims.

According to a first aspect, there is provided an apparatus comprising: at least one processor and at least one memory including a computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: communicate with a first network entity using a first communication protocol; communicate, using at least one bearer, with a second network entity using a second communication protocol; and limit transmission of the uplink data to at least one of the first and second network entities so as to avoid exceeding a first aggregate maximum bit rate concerning the at least one bearer.

The at least one memory and the computer program code may be further configured to, with the at least one processor, cause the apparatus to determine that the transmission of uplink data associated with the at least one bearer would exceed a first aggregate maximum bit rate and to limit the transmission of the uplink data in response to this determination.

The at least one memory and the computer program code may be further configured to, with the at least one processor, cause the apparatus to transmit the uplink data to only the second network entity.

The at least one memory and the computer program code may be further configured to, with the at least one processor, cause the apparatus to transmit the uplink data to the first and second network entities at the same aggregate bit rate. The at least one memory and the computer program code may be further configured to, with the at least one processor, cause the apparatus to transmit at least part of the uplink data to the first network entity,

The at least one memory and the computer program code may be further configured to, with the at least one processor, limit transmission of uplink data to avoid exceeding the first aggregate maximum bit rate by limiting the rate at which uplink data at a first protocol level in the apparatus is provided to a lower protocol level in the apparatus for transmission on the second protocol network.

The at least one memory and the computer program code may be further configured to, with the at least one processor, limit transmission of uplink data to avoid exceeding the first aggregate maximum bit rate by limiting the rate at which data at a first protocol level in the apparatus is reported to the first network entity as being pending for transmission. Data may be reported to the first network entity as being pending for transmission by transmitting a report of a buffer status of the apparatus.

The apparatus may be configured to determine the first aggregate maximum bit rate for transmitting uplink data following receipt from the first network entity of an indication of the first aggregate maximum bit rate.

The first aggregate maximum bit rate may be only an aggregate maximum bit rate for the at least one bearer.

The at least one memory and the computer program code may be further configured to, with the at least one processor, cause the apparatus to receive uplink scheduling decisions from the first network entity, and limiting the rate at which uplink data at a first protocol level in the apparatus is provided to a lower protocol level in the apparatus for transmission on the second protocol network based at least in part on said uplink scheduling decisions.

The at least one memory and the computer program code may be further configured to, with the at least one processor, cause the apparatus to receive from the first network entity at least one averaging period indicating a duration outside of which the first aggregate maximum bit rate may not be exceeded.

The at least one memory and the computer program code may be further configured to, with the at least one processor, cause the apparatus to receive from the first network entity a maximum packet size for transmission of uplink data packets, and to limit transmission of the uplink data to accord with the indicated maximum packet size.

The at least one memory and the computer program code may be further configured to, with the at least one processor, cause the apparatus to limit the transmission of the uplink data so as to avoid exceeding the first aggregate maximum bit rate at the Packet Data Convergence Protocol layer.

The at least one memory and the computer program code may be further configured to, with the at least one processor, cause the apparatus to limit the transmission of the uplink data so as to avoid exceeding the first aggregate maximum bit rate using a token-based mechanism, such that the uplink data transmissions over the first and/or second communication protocols are subject to the availability of tokens.

According to a second aspect, there is provided an apparatus comprising: at least one processor and at least one memory including a computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: communicate with a user device according to a first protocol, the user device being configured to communicate with a network entity according to a second protocol; determine a first aggregate maximum bit rate concerning at least one bearer over which the user equipment is configured to transmit uplink data to at least the network entity; and transmit an indication of the first aggregate maximum bit rate to the user equipment.

The at least one memory and the computer program code may be further configured to, with the at least one processor, cause the apparatus to: determine a second aggregate maximum bit rate for at least one bearer over which the user equipment is configured to transmit uplink data to only the apparatus; use the second aggregate maximum bit rate to determine a scheduling decision for transmitting uplink data from the user equipment; and transmit the scheduling decision to the user equipment.

The at least one memory and the computer program code may be further configured to, with the at least one processor, cause the apparatus to receive, from the user equipment, uplink data belonging to the at least one bearer associated with the first aggregate maximum bit rate. The at least one memory and the computer program code may be further configured to, with the at least one processor, cause the apparatus to transmit to the user equipment at least one averaging period indicating a duration outside of which the aggregate maximum bit rate may not be exceeded.

The at least one memory and the computer program code may be further configured to, with the at least one processor, cause the apparatus to transmit to the user equipment a maximum packet size for transmission of uplink data packets.

According to a third aspect, there is provided a method comprising:

communicating with a first network entity using a first communication protocol;

communicating, using at least one bearer, with a second network entity using a second communication protocol; and limiting transmission of the uplink data to at least one of the first and second network entities so as to avoid exceeding a first aggregate maximum bit rate concerning the at least one bearer.

The method may further comprise determining that the transmission of uplink data associated with the at least one bearer would exceed a first aggregate maximum bit rate, wherein the limiting the transmission of the uplink data is response to this determination.

The method may further comprise transmitting the uplink data to only the second network entity.

The method may further comprise transmitting the uplink data to the first and second network entities at the same aggregate bit rate.

The method may further comprise transmitting at least part of the uplink data to the first network entity.

Limiting transmission of uplink data to avoid exceeding the first aggregate maximum bit rate may comprises limiting the rate at which uplink data at a first protocol level in the apparatus is provided to a lower protocol level in the apparatus for transmission on the second protocol network.

Limiting transmission of uplink data to avoid exceeding the first aggregate maximum bit rate may comprise limiting the rate at which data at a first protocol level in the apparatus is reported to the first network entity as being pending for

transmission. Data may be reported to the first network entity as being pending for transmission by transmitting a report of a buffer status of the apparatus. The method may further comprise determining a first aggregate maximum bit rate for transmitting uplink data following receipt from the first network entity of an indication of the first aggregate maximum bit rate, wherein the first aggregate maximum bit rate is only an aggregate maximum bit rate for the at least one bearer.

The method may further comprise receiving uplink scheduling decisions from the first network entity, and limiting the rate at which uplink data at a first protocol level in the apparatus is provided to a lower protocol level in the apparatus for transmission on the second protocol network based at least in part on said uplink scheduling decisions.

The method may further comprise receiving from the first network entity at least one averaging period indicating a duration outside of which the first aggregate maximum bit rate may not be exceeded.

The method may further comprise receiving from the first network entity a maximum packet size for transmission of uplink data packets, and wherein limiting transmission of the uplink data comprises limiting the size of a packet to be transmitted to accord with the indicated maximum packet size.

Limiting the transmission of the uplink data so as to avoid exceeding the first aggregate maximum bit rate may be performed at the Packet Data Convergence

Protocol layer.

The method may further comprise limiting the transmission of the uplink data so as to avoid exceeding the first aggregate maximum bit rate using a token-based mechanism, such that the uplink data transmissions over the first and/or second communication protocols are subject to the availability of tokens.

According to a fourth aspect, there is provided a method comprising communicating with a user device according to a first protocol, the user device being configured to communicate with a network entity according to a second protocol; determining a first aggregate maximum bit rate concerning at least one bearer over which the user equipment is configured to transmit uplink data to at least the network entity; and transmitting an indication of the first aggregate maximum bit rate to the user equipment.

The method may further comprise determining a second aggregate maximum bit rate for at least one bearer over which the user equipment is configured to transmit uplink data to using only the first protocol; using the second aggregate maximum bit rate to determine a scheduling decision for transmitting uplink data from the user equipment; and transmitting the scheduling decision to the user equipment.

The method may further comprise receiving, from the user equipment, uplink data belonging to the at least one bearer associated with the first aggregate maximum bit rate.

The method may further comprise transmitting to the user equipment at least one averaging period indicating a duration outside of which the aggregate maximum bit rate may not be exceeded.

The method may further comprise transmitting to the user equipment a maximum packet size for transmission of uplink data packets.

According to a fifth aspect, there is provided a computer program product for a computer, comprising software code portions for performing the steps of any of claims 21 to 40 when said product is run on the computer.

According to a sixth aspect, there is provided an apparatus comprising means for performing a method according to any one of claims 21 to 40.

According to a seventh aspect, there is provided a system comprising: a user equipment comprising apparatus according to any of claims 1 to 15; a first network entity comprising apparatus according to any of claims 18 to 20; and a second network entity configured to communicate with the user equipment using the at least one bearer according to claim 1.

BRIEF DESCRIPTION OF THE FIGURES

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

Figure 1 shows a schematic diagram of an example communication system comprising a base station and a plurality of communication devices;

Figure 2 shows a schematic diagram, of an example mobile communication device;

Figure 3 shows a schematic diagram of an example WLAN network;

Figures 4A and 4B show protocol architectures for a network and user equipment;

Figure 5 shows a flowchart of a process that may be applied at a user equipment; Figure 6 shows a flowchart of a process that may be applied by a network equipment;

Figure 7 shows a schematic diagram of an example network entity; and Figure 8 shows a schematic diagram of an example user equipment.

DETAILED DESCRIPTION

In general, the following relates to a system in which a user equipment is configured to communicate with first and second network entities using respective communication protocols. The first network, which comprises the first network entity, is configured to receive uplink data from the user equipment via at least one of the first and second network entities. In other words, the user equipment is able to transmit uplink data to a control node in the first network via an access point in a second, different, network. The uplink data to be transmitted to the first network is transmitted using at least one bearer defined by the first network. A bearer may be viewed as a virtual concept that defines how user equipment data is treated as it travels across a network. In other words, a bearer may be seen as a set of parameters that defines data-specific treatment. For example, a bearer may define a minimum data rate for a user of a user equipment. Thus, uplink transmissions made in accordance with at least one bearer correspond to those uplink transmissions that are treated in a predefined way. It is understood that throughout the following, references to the at least one bearer refers to bearer(s) defined by the first network. In particular, the bearers may be bearers defined by a 3GPP network level entity.

In the presently described system, the first network is configured to signal to the user equipment an aggregate maximum bitrate associated with the at least one bearer. The user equipment is configured to use this signalled aggregate maximum bitrate to limit the amount of uplink data transmitted over the at least one bearer regardless of the communication protocol used by the user equipment to transmit the uplink data for that at least one bearer. This may be achieved by the user equipment applying a throttling mechanism, which dynamically causes uplink data rates to be adjusted to avoid exceeding the signalled aggregate maximum bit rate. For communication protocols, such as WLAN, in which the user equipment controls the scheduling of transmitted uplink data, this may be achieved by limiting the amount of data passed down from a higher protocol layer to a lower protocol layer for transmission over the WLAN link. For example, the mobile device may limit the amount of data passed down from an IP level of its WLAN protocol stack to the MAC/PHY layers of its WLAN protocol stack. For communication protocols, such as 3GPP/LTE, in which a network level entity controls the scheduling of uplink transmissions, this may be achieved by the user equipment informing a 3GPP network entity that it has only a predetermined amount of data for transmission, the predetermined amount being selected by the user equipment so as to avoid exceeding the aggregate maximum bit rate for the at least one bearer. The 3GPP network entity may then use this signalled predetermined amount to schedule uplink transmissions on the at least one bearer from the user equipment to the 3GPP network. It is understood, that in both of these examples, the user equipment may consider the data to be transmitted over each of the different network links when deciding when and how to avoid exceeding the maximum bit rate. The user equipment may be configured to limit uplink data transmissions over only one communication protocol. Alternatively, the user equipment may be configured to limit uplink data communications over both communication protocols. In other words, the user equipment may consider the transmissions made or to be made over each of the different communication protocols before applying a throttling mechanism to the transmission of uplink data over at least one bearer, the throttling mechanism causing the transmission of the uplink data to be limited.

Before explaining in detail the examples, certain general principles of a wireless communication system and mobile communication devices are briefly explained with reference to Figures 1 to 2 to assist in understanding the technology underlying the described examples.

In a wireless communication system 100, such as that shown in figure 1 , mobile communication devices or user equipment (UE) 102, 104, 105 are provided wireless access via at least one base station or similar wireless transmitting and/or receiving node or point. Base stations are typically controlled by at least one appropriate controller apparatus, so as to enable operation thereof and management of mobile communication devices in communication with the base stations. The controller apparatus may be located in a radio access network (e.g. wireless communication system 100) or in a core network (CN) (not shown) and may be implemented as one central apparatus or its functionality may be distributed over several apparatus. The controller apparatus may be part of the base station and/or provided by a separate entity such as a Radio Network Controller (RNC). In Figure 1 control apparatus 108 and 109 are shown to control the respective macro level base stations 108 and 107, The control apparatus of a base station can be interconnected with other control entities. The control apparatus is typically provided with memory capacity and at least one data processor. The control apparatus and functions may be distributed between a plurality of control units. In some systems, the control apparatus may additionally or alternatively be provided in a radio network controller,

LTE systems may however be considered to have a so-called "flat"

architecture, without the provision of RNCs; rather the (e)NB is in communication with a system architecture evolution gateway (SAE-GW) and a mobility management entity (MME), which entities may also be pooled meaning that a plurality of these nodes may serve a plurality (set) of (e)NBs. Each UE is served by only one MME and/or S-GW at a time and the (e)NB keeps track of current association, SAE-GW is a "high-level" user plane core network element in LTE, which may consist of the S- GW and the P-GW (serving gateway and packet data network gateway,

respectively). The functionalities of the S-GW and P-GW are separated and they are not required to be co-located.

In Figure 1 base stations 106 and 107 are shown as connected to a wider communications network 1 13 via gateway 1 12, A further gateway function may be provided to connect to another network.

The smaller base stations 1 16, 1 18 and 120 may also be connected to the network 1 13, for example by a separate gateway function and/or via the controllers of the macro level stations. The base stations 1 16, 118 and 120 may be pico or femto level base stations or the like. In the example, stations 1 16 and 1 18 are connected via a gateway 1 1 1 whilst station 120 connects via the controller apparatus 108, In some embodiments, the smaller stations may not be provided. Smaller base stations 116, 1 18 and 120 may be part of a second network, for example WLAN and may be WLAN APs.

A possible mobile communication device will now be described in more detail with reference to Figure 2 showing a schematic, partially sectioned view of a communication device 200. Such a communication device is often referred to as user equipment (UE) or terminal. An appropriate mobile communication device may be provided by any device capable of sending and receiving radio signals. Non- limiting examples comprise a mobile station (MS) or mobile device such as a mobile phone or what is known as a 'smart phone', a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle), personal data assistant (PDA) or a tablet provided with wireless communication capabilities, or any combinations of these or the like. A mobile communication device may provide, for example, communication of data for carrying communications such as voice, electronic mail (email), text message, multimedia and so on. Users may thus be offered and provided numerous services via their communication devices. Non- limiting examples of these services comprise two-way or multi-way calls, data communication or multimedia services or simply an access to a data

communications network system, such as the Internet. Users may also be provided broadcast or multicast data. Non-limiting examples of the content comprise

downloads, television and radio programs, videos, advertisements, various alerts and other information.

The mobile device 200 may receive signals over an air or radio interface 207 via appropriate apparatus for receiving and may transmit signals via appropriate apparatus for transmitting radio signals. In Figure 2 transceiver apparatus is designated schematically by block 206. The transceiver apparatus 206 may be provided for example by means of a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device.

A mobile device is typically provided with at least one data processing entity

201 , at least one memory 202 and other possible components 203 for use in software and hardware aided execution of tasks it is designed to perform, including control of access to and communications with access systems and other

communication devices. The data processing, storage and other relevant control apparatus can be provided on an appropriate circuit board and/or in chipsets. This feature is denoted by reference 204. The user may control the operation of the mobile device by means of a suitable user interface such as key pad 205, voice commands, touch sensitive screen or pad, combinations thereof or the like. A display 208, a speaker and a microphone can be also provided. Furthermore, a mobile communication device may comprise appropriate connectors (either wired or wireless) to other devices and/or for connecting external accessories, for example hands-free equipment, thereto.

The communication devices 102, 104, 105 may access the communication system based on various access techniques, such as code division multiple access (CDMA), or wideband CDMA (WCDMA). Other non-limiting examples comprise time division multiple access (TDMA), frequency division multiple access (FDMA) and various schemes thereof such as the interleaved frequency division multiple access (IFDMA), single carrier frequency division multiple access (SC-FDMA) and

orthogonal frequency division multiple access (OFDMA), space division multiple access (SOMA) and so on.

An example of wireless communication systems are architectures

standardized by the 3rd Generation Partnership Project (3GPP). A latest 3GPP based development is often referred to as the long term evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio-access technology. The various development stages of the 3GPP specifications are referred to as releases. More recent developments of the LTE are often referred to as LTE Advanced (LTE- A). The LTE employs a mobile architecture known as the Evolved Universal

Terrestrial Radio Access Network (E-UTRAN). Base stations of such systems are known as evolved or enhanced Node Bs (eNBs) and provide E-UTRAN features such as user plane Packet Data Convergence/Radio Link Control/Medium Access Control/Physical layer protocol (PDCP/RLC AC/PHY) and control plane Radio Resource Control (RRC) protocol terminations towards the communication devices. Other examples of radio access system comprise those provided by base stations of systems that are based on technologies such as wireless local area network (WLAN) and/or WiMax (Worldwide Interoperability for Microwave Access). A base station can provide coverage for an entire cell or similar radio service area.

The following relates to LTE-WLAN interworking. Packet-wise aggregation between LTE and WLAN may be performed and the UE served simultaneously by both radio networks. Extending the benefits of integrated LTE-WLAN access to non- collocated scenarios where the LTE eNB and WLAN Access Point (AP) may be connected through non-ideal backhauls have been considered. Conceptually, this may be similar to LTE dual connectivity (DC) bearer split functionality (a.k.a. option 3C) recently standardized in 3GPP. In this scenario, the LTE eNB may act as the master node and the WLAN AP as the slave node. A proper combination of the data payload would be required at the UE side. LTE-WLAN radio aggregation proposals aim to provide support for network-control mechanisms which enable spectrum aggregation gains (including fine load balancing between LTE and WLAN). In 3GPP/WLAN aggregation, at least two possible ways of the user equipment utilising the WLAN for transmitting uplink data are known. One way is shown in Figure 4A and another way is shown in Figure 4B.

Figure 4A, illustrates a user plane architecture for a network entity and/or a user equipment in an embodiment in which a user equipment is expected to transmit all uplink data for a particular 3GPP bearer via a WLAN access point/network entity. In the architecture 401A for interacting with the 3GPP network entity, there is provided at least one IP-level stack comprising at least two parts (labelled 402A and 402A'), each part being associated with a respective communication protocol. One of these parts 402A is associated with a corresponding radio link control (RLC) level part 403A and a media access control (MAC) part 404A in the protocol stack for the 3GPP network entity. The other of these PDCP level parts 402A' is associated with a corresponding RLC level part 405A and a MAC part 406A in the protocol stack for the WLAN network entity. Figure 4A corresponds to Alternative 2C in 3GPP TR 36.842 V12.0.0.

Figure 4B illustrates a user plane architecture for a network entity and/or a user equipment in an embodiment in which a user equipment is expected to transmit only part of the uplink data for a particular 3GPP bearer via a WLAN access point/network entity. In the architecture 401 B for interacting with the 3GPP network entity, there is provided at least one IP-level stack comprising at least two parts (labelled 402B and 402B'), each part being associated with a respective

communication protocol. One of these parts 402B is associated with a corresponding radio link control (RLC) level part 403B and a media access control (MAC) part 404B in the protocol stack for the 3GPP network entity. The other of these PDCP level parts 402B' is associated with a corresponding RLC level part 405B and a MAC part 406B in the protocol stack for the WLAN network entity, in addition to an RLC part 407B and the MAC part 404B in the 3GPP network entity. Figure 4B corresponds to Alternative 3C in 3GPP TR 36.842 V12.0.0.

Since Release 8, 3GPP specifications have supported several mechanisms for offloading traffic from a 3GPP access network to a Wi-Fi access network. Both seamless (i.e. retaining the IP address) and non-seamless service continuation may be supported for such radio access technology (RAT) change between Wi-Fi and 3GPP access networks including UMTS and LTE, depending on the method. A WLAN Interworking Gateway (WIG) comprises a set of functionalities that may be separate to or integrated in existing WLAN Access Gateways (WAGs). A protocol stack for allowing reliable transmission over the WLAN network

encompasses a solution that exploits eNB controlled aggregation a-la LTE DC 3C solution, but it also provides a solution where the WIG can receive internet protocol (IP) packets from either the eNB or other network elements (S/P-GW). Such a solution covers both the case where more or less tight radio aggregation or offloading is used,

A legacy WLAN network is capable of standalone activity (i.e. independently carrying traffic of directly affiliated, and not offloaded UEs) also. An example of a WLAN network can be seen in Figure 3. Such a network may be composed of at least: a WIG functionality 130, for communicating and interworking with a 3GPP RAN 135, a set of APs 132 that carry the traffic over the air to/from the network, a

Dynamic Host Control Protocol 134 (DHCP or DHCPv6 in case of IPv6 network) server, able to independently assign the IP addresses to the standalone UEs, an IP addresses database 136 that collects the pool of the available IP addresses for use in the WLAN network (an IP addresses database may contain to which MAC address (LIE) the IP address is bound to, and other information (e.g. but not limited to the time-to-live of such binding)). The WLAN can support dynamic MAC address assignment, for enhancing privacy and security. Such a feature may be based on a Local MAC Addressing (LMA) server.

The WLAN network may comprise a MAC address database 138, containing (but not limited to) the list of currently assigned and currently available MAC addresses to be used in the local network.

The Dynamic Host Control Protocol 134 may be used in IP networks for dynamically allocating and reclaiming IP addresses in the network. The protocol may enable the request of several IP parameters, and it is based on a client-server interaction model. The dynamic MAC address assignment (or Local MAC Addressing - LMA) is a technique similar to DHCP for enhancing privacy and security in public networks.

The Network Address Translation (NAT) is a set of techniques used for mapping an IP address into another while the packet is in transit in a routing device or a gateway. Such procedures may be used for IP masquerading, hiding internal IP addresses within a network to the external world. This feature is typically used in enterprise LANs. Translation generally is made between two IPv4 addresses

(NAT44) or IPv6 and IPv4 address (NAT64).

One main difference between the 802.1 1 MAC of WLAN and the LTE MAC is that in the LTE-MAC, data transmissions in both the uplink and the downlink are duly controlled by the scheduler on the network side. For WLAN, the access is instead distributed. By this, it is meant that in WLAN, all parties (i.e. user equipment and access points alike) contend for the radio resources in order to transmit the data that they have pending. To this end, the WLAN access point broadcasts WLAN

contention parameters for use by all user equipments located in the WLAN

broadcast area. This means that, unlike in LTE, when a WLAN link is used to transmit uplink data for LTE, it is difficult in WLAN to ensure that an aggregate maximum bit rate is not exceeded.

As mentioned above, in the following there is discussed a user equipment (more generally, an apparatus), that is configured to cause a rate limiting mechanism to be applied to uplink data transmission over at least one bearer, so that an aggregate maximum bit rate over the at least one bearer is not exceeded. The aggregate maximum bit rate is applied to uplink transmissions of the at least one bearer made from the user equipment to network entities via any communication protocol. It is understood that a bearer may be viewed as a virtual concept that defines how user equipment data is treated as it travels across a network. In other words, a bearer may be seen as a set of parameters that defines data-specific treatment. Thus, uplink transmissions made in accordance with at least one bearer correspond to those uplink transmissions that are treated in a predefined way. In the present case, the at least one bearer is defined by the first network (i.e. it is a bearer of the first network). At least part of the uplink transmissions made on the at least one bearers may be made via a second network.

Some of the potential operations of a user equipment configured to implement the above-described aspects are outlined in the flow chart of Figure 5.

At 501 , the user equipment is configured to communicate with a first network entity using a first communication protocol. The first network entity may be an eNB. More specifically, the eNB may be a master eNB defined in Release 13. The communication protocol may be a 3GPP specification defined communication protocol. More specifically, the communication protocol may be an LTE

communication protocol. At 502, the user equipment is configured to communicate, using at least one bearer, with a second network entity using a second communication protocol. The at least one bearer may be defined by a network entity in the first communication network i.e. by a 3GPP network entity. The second network entity may be an access point of a WLAN network. The second communication protocol may be a

communication protocol of a WLAN network. More specifically, the second

communication protocol may be an 802.1 1 specification defined communication protocol. As mentioned above, a bearer represents a defined treatment of user data.

At 503, the user equipment is configured to limit transmission of uplink data to at least one of the first and second network entities so as to avoid exceeding a first aggregate maximum bit rate concerning the at least one bearer. In other words, the user equipment applies a rate throttling mechanism to inhibit (or otherwise limit) the uplink transmissions for those at least one bearers. Where the user equipment does not have direct control over scheduling its uplink data transmissions under a particular communication protocol, it may manipulate the decision of the entity that does schedule its uplink data transmissions in order to avoid exceeding the first aggregate maximum bit rate. Examples of these are discussed below. The first aggregate maximum bit rate is a bit rate that is received from a network entity in the first communication network (e.g. from an eNB in the 3GPP network). The first aggregate maximum bit rate indicates the maximum amount of uplink data to be transmitted by the user equipment in a given period over at least one non- guaranteed bit rate bearer. As mentioned above, the at least one bearer is defined by the network entity in the first network. The aggregate maximum bit rate is defined in a current 3GPP Release to apply to all non-guaranteed bit rate bearers, and so the first aggregate maximum bit rate may be said to indicate the maximum amount of uplink data to be transmitted by the user equipment per unit time over all non- guaranteed bit rate bearers of the user equipment. The user equipment may be configured to limit uplink transmissions to the first/3GPP network entity and/or to the second WLAN network entity.

It is thus understood that user equipment is configured to limit transmission of uplink data in dependence on receipt from the first 3GPP communication network of a first aggregate maximum bitrate. This allows the user equipment to avoid exceeding the first aggregate maximum bit rate concerning the at least one bearer. Depending on particular embodiments described below, the user equipment may or may not make an explicit determination that the transmission of the uplink data would exceed the aggregate maximum bit rate.

The rate throttling mechanism may be applied in a variety of ways. For example, if the rate is to be limited on the second network protocol (e.g. on a WLAN network), the rate at which uplink data at a first protocol level of the user equipment is provided to a lower protocol level of the user equipment for transmission on the second protocol network is limited/reduced, or otherwise set to ensure that he aggregate maximum transmission rate is not exceeded. For example, for networks in which the user equipment is configured to schedule uplink data transmissions, an IP level in the user equipment may limit the information passed to the lower layers (e.g. RLC and/or MAC layers) of the user equipment for transmission over the second network. For networks in which a network level entity is configured to control the scheduling of uplink data transmissions from the user equipment (e.g. 3GPP/LTE networks), the amount of data at a first protocol level of the user equipment that is reported to the network entity (e.g. the first network entity) as being pending for transmission may be limited. For example, the user equipment may report to the first network entity that it has less data for transmission over the at least one bearer than it actually has for transmission over the at least one bearer. The first network entity will then schedule the transmission of the uplink data traffic and transmit scheduling information indicative of this to the user equipment. The data may be reported to the first network entity as being pending for transmission by transmitting a report of a buffer status of the apparatus. In 3GPP terminology, the report may be a Buffer Status Report. In 3GPP terminology, the limiting/throttling mechanism controlled by the user equipment may be implemented at the PDCP layer.

The user equipment may be configured to determine that the transmission of uplink data associated with the at least one bearer would exceed the first aggregate maximum bit rate. In other words, the user equipment determines that the uplink data it has for transmission on its non-guaranteed bit rate bearers within a predetermined time period would, if it were all transmitted within that predetermined time period, exceed the first aggregate maximum bit rate.

The user equipment may be configured to transmit the uplink data using only the second network entity i.e. using only the WLAN protocol. Alternatively, the user equipment may be configured to transmit at least part of the uplink data using the first network entity i.e. using the 3GPP protocol. As mentioned above, in the present case the user equipment may be configured to transmit at least part of the uplink data using the second network entity i.e. using the WLAN protocol.

The user equipment may be configured to limit transmission of uplink data such that uplink transmissions to the first and second network entities are performed at the same aggregate bit rate. By this, it is meant that the user equipment causes the transmission of the uplink data to be such that the aggregate bit rate of uplink data transmitted on the 3GPP network is the same as the aggregate bit rate of uplink data transmitted on the WLAN network. This may be arranged by the user equipment using some of the rate throttling mechanisms detailed above (e.g.

providing less data to the RLC and/or MAC layers for transmission and/or refraining from reporting all of the data for uplink transmission currently held in a buffer to a network-based scheduling entity).

The user equipment may be configured to receive indications from the first/3GPP network entity regarding at least one parameter. Notably, an indication of the aggregate maximum bit rate may be provided to the user terminal via an eNB.

The user equipment may use this indication to determine the first aggregate maximum bit rate for transmitting uplink data.

The user equipment may also be configured to receive an indication from the first network entity of at least one averaging period. An averaging period indicates a duration in time, outside of which the aggregate maximum bit rate may not be exceeded. Thus the user equipment may be configured to only apply the rate throttling mechanism as defined by an averaging period.

The user equipment may be further configured to receive from the first network entity a maximum packet size for transmission of uplink data packets. The user equipment may use this maximum packet size to set a limit to the size of a packet to be transmitted in the uplink. In other words, the user equipment may be configured to use the received indication of maximum packet size to set a maximum size of packets to be transmitted on the uplink.

The first aggregate maximum bit rate may be only an aggregate maximum bit rate for the at least one bearer for which uplink data is transmitted using, at least in part, the second network entity. By this, it is meant that uplink data on bearers not served by the second network entity may be transmitted at an aggregate maximum rate that is different to the first aggregate maximum bit rate, whether above or below the first aggregate maximum bit rate. A second aggregate maximum bit rate may be used for at least one bearer for which uplink data is transmitted using only the first network. In other words, the first aggregate maximum bit rate may apply to bearers that are at least partly associated with the second WLAN network entity (which may or may not also be associated with the first/3GPP network entity) and the second aggregate maximum bit rate may apply only to uplink transmissions on bearers that are not associated with the second WLAN network entity. This system may be viewed as the 3GPP network having an overall maximum bit rate that is split into two portions. One portion (the first maximum bitrate) applies only to bearers served at least partly by a WLAN (the second network). This means that this portion may also apply to those bearers served by both a WLAN and a 3GPP network. The other portion (the second maximum bitrate) applies only to bearers served only by a 3GPP network (the first network). The 3GPP network may be configured to signal information regarding the first portion to a user equipment. The information is such that it enables the user equipment to cause the uplink data transmission rate to be limited to the first aggregate maximum bit rate. The 3GPP network may be configured to apply the second maximum bitrate itself, by scheduling uplink transmissions in such a way that the second maximum bitrate is not exceeded.

On receipt of scheduling decisions from the 3GPP network, the user equipment may be configured to limit the rate at which uplink data at a first protocol level in the user equipment is provided to a lower protocol level in the apparatus for transmission on the second protocol network based at least in part on said uplink scheduling decisions, where the lower protocol level is at a lower protocol level relative to the first protocol level.

The user equipment may be configured to limit the aggregate bit rate to the first aggregate maximum bit rate using a token-based mechanism, such that the uplink data transmissions over the first and/or second communication protocols are subject to the availability of at least one token. At its simplest, the token mechanism may be the token-bucket mechanism applied in the uplink of the LTE-MAC Logical- Channel Prioritization mechanism in Release 12. In this system, there is a single

"bucket" that is shared by all of the bearers under the user equipment's rate-throttling management scheme described above. When a PDCP PDU is to be transmitted over WLAN or over 3GPP, the submission of the PDCP PDU for transmission is dependent on the tokens available in the shared bucket: if there are no tokens, no transmission occurs. The tokens may be removed in dependence on the size of a transmitted packet. New tokens may be added to the bucket as time passes. The number of tokens in the bucket and/or the rate at which new tokens are added to the bucket, may be parameterised by the first aggregate maximum bit rate. Thus, the indication of the first aggregate maximum bit rate received from the first/3GPP network entity may be a set of descriptors for parameterising the bucket-token mechanism. It is also understood that the indication itself may be explicitly the first aggregate maximum bit rate, and the user equipment may itself use this explicit indication to parameterise the bucket-token mechanism using a predetermined set of rules for doing so.

There is also described herein the 3GPP network entity (e.g. the eNB) that is configured to receive uplink traffic from the user equipment in the 3GPP network. A flow chart illustrating at least part of a process executed by such a 3GPP network entity is provided in Figure 6.

In 601 , the 3GPP network entity is configured to communicate with a user device according to a first protocol (i.e. the 3GPP protocol). As mentioned above the user device is also configured to communicate with a network entity according to a second protocol (WLAN in the present case).

At 602, the 3GPP network entity is configured to determine a first aggregate maximum bit rate concerning at least one bearer over which the user equipment is configured to transmit uplink data to at least the WLAN network entity.

At 603, the 3GPP network entity is configured to transmit an indication of the first aggregate maximum bit rate to the user equipment.

The 3GPP network entity may be further configured to determine a second aggregate maximum bit rate for at least one bearer over which the user equipment is configured to transmit uplink data to only the apparatus. The 3GPP network entity may be configured to make a scheduling decision based on the second aggregate maximum bit rate for transmitting uplink data from the user equipment to the 3GPP network entity. The scheduling decision is then transmitted to the user equipment. It is thus understood that the second aggregate maximum bit rate is enforced by the 3GPP network and the first aggregate maximum bit rate is enforced (or at least controlled) by the user equipment. It is further noted that the scheduling decision for transmitting uplink data may change from one transmission time interval to another transmission time interval and is thus not considered to be an indication of the second aggregate maximum bit rate. This is because aggregate maximum bit rates are semi-static parameters and do not change as frequently as scheduling decisions. In contrast, the indication provided by the 3GPP network entity to the user equipment of the first aggregate maximum bit rate is more than merely a scheduling decision, and it must allow for additional transmissions associated with the bearers of the first aggregate maximum bit rate to be at least partially controlled by the user equipment. The indication of the first aggregate maximum bit rate may thus be provided by an explicit indication, and will not be provided through a scheduling decision from the 3GPP network.

The 3GPP network entity may be configured to receive, from the user equipment, uplink data belonging to the at least one bearer associated with the first aggregate maximum bit rate. This is because although this uplink data is at least partially transmitted by the WLAN network, there remains the possibility of the user equipment causing for transmission of some of this uplink data through the 3GPP network.

The network equipment may be configured to transmit to the user equipment at least one averaging period indicating a duration outside of which the aggregate maximum bit rate may not be exceeded. This is applied by the user equipment as described in the case above.

The network equipment may be configured to transmit to the user equipment a maximum packet size for transmission of uplink data packets. This is applied by the user equipment as described in the above.

An example network equipment for the 3GPP system is shown in Figure 7. Figure 7 shows an example of a control apparatus 300 for a communication system, for example to be coupled to and/or for controlling a station of an access system, such as a RAN node, e.g. a base station or (e) node B, or a node of a core network such as an MME. The method may be implanted in a single control apparatus or across more than one control apparatus. The control apparatus may be integrated with or external to a node or module of a core network or RAN. In some

embodiments, base stations comprise a separate control apparatus unit or module. In other embodiments, the control apparatus can be another network element such as a radio network controller or a spectrum controller. In some embodiments, each base station may have such a control apparatus as well as a control apparatus being provided in a radio network controller. The control apparatus 300 can be arranged to provide control on communications in the service area of the system. The control apparatus 300 comprises at least one memory 301 , at least one data processing unit 302, 303 and an input/output interface 304, Via the interface the control apparatus can be coupled to a receiver and a transmitter of the base station. The receiver and/or the transmitter may be implemented as a radio front end or a remote radio head. For example the control apparatus 300 can be configured to execute an appropriate software code to provide the control functions. Control functions may comprise communicating with a user device according to a first protocol, the user device being configured to communicate with a network entity according to a second protocol; determining a first aggregate maximum bit rate for at least one bearer over which the user equipment is configured to transmit uplink data to at least the network entity; and transmitting an indication of the first aggregate maximum bit rate to the user equipment.

Control apparatus 300 may be included in a chipset or modem apparatus. A chipset or modem apparatus which includes apparatus 300 may be included in a control node such as an eNB.

An example of a control apparatus 800 associated with the user equipment is shown in Figure 8. Control apparatus 800 comprises means 810 for communicating with a first network entity using a first communication protocol; communicating, using at least one bearer, with a second network entity using a second communication protocol; determining that the transmission of uplink data associated with the at least one bearer would exceed a first aggregate maximum bit rate for transmitting uplink data on the at least one bearer; and in response to the determination, liming transmission of the uplink data so as to avoid exceeding the first aggregate maximum bit rate.

Apparatus 800 may be included in a chipset or modem apparatus. A chipset or modem apparatus which includes apparatus 800 may be included in the user equipment.

It should be understood that the apparatuses may comprise or be coupled to other units or modules etc., such as radio parts or radio heads, used in or for transmission and/or reception. Although the apparatuses have been described as one entity, different modules and memory may be implemented in one or more physical or logical entities. It is noted that whilst embodiments have been described in relation to 3GPP and WLAN, similar principles can be applied in relation to other cellular networks and wireless local area networks and to any other communication system where interworking between two networks is supported. For example, although the description assumed WLAN as the network of the second access point/node, the second network may be any other radio network as well. For example, the first access node may operate on a licensed band whereas the second access point may be operating on an unlicensed band (as in e.g. LTE-unlicensed, LTE-U, or licensed assisted access, LAA), Therefore, although certain embodiments were described above by way of example with reference to certain example architectures for wireless networks, technologies and standards, embodiments may be applied to any other suitable forms of communication systems than those illustrated and described herein.

It is also noted herein that while the above describes example embodiments, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention.

In general, the various embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects of the invention may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The embodiments of this invention may be implemented by computer software executable by a data processor of the mobile device, such as in the processor entity, or by hardware, or by a combination of software and hardware. Computer software or program, also called program product, including software routines, applets and/or macros, may be stored in any apparatus-readable data storage medium and they comprise program instructions to perform particular tasks. A computer program product may comprise one or more computer-executable components which, when the program is run, are configured to carry out embodiments. The one or more computer-executable components may be at least one software code or portions of it.

Further in this regard it should be noted that any blocks of the logic flow as in the Figures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD. The physical media is a non-transitory media.

The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may comprise one or more of general purpose computers, special purpose

computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), FPGA, gate level circuits and processors based on multi core processor architecture, as non-limiting examples.

Embodiments of the inventions may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

The foregoing description has provided by way of non-limiting examples a full and informative description of the exemplary embodiment of this invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, ail such and similar modifications of the teachings of this invention will still fall within the scope of this invention as defined in the appended claims. Indeed there is a further embodiment comprising a combination of one or more embodiments with any of the other embodiments previously discussed.