WO2014111137A1

WO2014111137A1 - Methods and apparatuses for setting temporary identifiers for a user equipment

Info

Publication number: WO2014111137A1
Application number: PCT/EP2013/050727
Authority: WO
Inventors: Jing He; Amaanat ALI; Karol Drazynski; Jeroen Wigard
Original assignee: Nokia Solutions And Networks Oy
Priority date: 2013-01-16
Filing date: 2013-01-16
Publication date: 2014-07-24

Abstract

A method comprising: setting first and second temporary identifiers for a user equipment; wherein said first temporary identifier is associated with a first cell; and said second temporary identifier is associated with at least two further cells at least partially overlapping with said first cell.

Description

DESCRIPTION

TITLE

METHODS AND APPARATUSES FOR SETTING TEMPORARY IDENTIFIERS FOR A USER EQUIPMENT The present invention relates to methods, apparatus and computer programs for using identifiers associated with user equipment.

A communication system can be seen as a facility that enables communication sessions between two or more entities such as fixed or mobile communication devices, base stations, servers and/or other communication nodes. A communication system and compatible communicating entities 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. For example, the standards, specifications and related protocols can define the manner how various aspects of communication shall be implemented between communicating devices. A communication can be carried on wired or wireless carriers. In a wireless communication system at least a part of communications between stations occurs over a wireless link.

Examples of wireless systems include public land mobile networks (PLMN) such as cellular networks, satellite based communication systems and different wireless local networks, for example wireless local area networks (WLAN). A wireless system can be divided into cells or other radio coverage or service areas. A radio service area is provided by a station. Radio service areas can overlap, and thus a communication device in an area can typically send signals to and receive signals from more than one station.

A user can access the communication system by means of an appropriate communication device. A communication device of a user is often referred to as user equipment (UE) or terminal. A communication device is provided with an appropriate signal receiving and transmitting arrangement for enabling communications with other parties. Typically a com- munication device is used for enabling receiving and transmission of communications such as speech and data. In wireless systems a communication device provides a transceiver station that can communicate with another communication device such as e.g. a base station and/or another user equipment. The communication device may access a carrier provided by a station, for example a base station, and transmit and/or receive communications on the carrier. An example of communication systems is an architecture that is being standardized by the 3rd Generation Partnership Project (3GPP). This system is often referred to as the Universal Mobile Telecommunications System (UMTS) radio-access technology. The UMTS may in- corporate Wideband Code Division Multiple Access (WCDMA) technology. The various development stages of the 3GPP specifications are referred to as releases.

A communication system can comprise different types of radio service areas providing transmission/reception points for the users. For example, the transmission/reception points can comprise wide area network nodes such as a macro Node-B (NB) which may, for example, provide coverage for an entire cell or similar radio service area. Network nodes can also be small or local radio service area network nodes, for example Home NBs (HNB), pico Node-Bs (pico-NB), or femto nodes. Some applications utilise radio remote heads (RRH) that are connected to for example an NB. The smaller radio service areas can be located wholly or partially within the larger radio service area. A user equipment may thus be located within, and thus communicate with, more than one radio service area. The nodes of the smaller radio service areas may be configured to support local offload. The local nodes can also, for example, be configured to ex- tend the range of a cell.

According to a first aspect there is provided a method comprising: setting first and second temporary identifiers for a user equipment; wherein said first temporary identifier is associated with a first cell; and said second temporary identifier is associated with at least two fur- ther cells at least partially overlapping with said first cell.

Preferably the method further comprises setting third and fourth temporary identifiers for said user equipment. Preferably said first and second temporary identifiers are configured to enable one of downlink and uplink communication, and said third and fourth temporary identifiers are configured to enable the other of downlink and uplink communication.

Preferably said first cell comprises a macro-cell and said at least two further cells comprise small-cells. Preferably said first cell and said at least two further cells are comprised in a Forward Access Channel Registration Area.

Preferably the method comprises transmitting a cell update message from said user equip- ment in order to obtain said temporary identifiers.

Preferably said method comprises transmitting information from said user equipment via said first cell or at least one of said two further cells, dependent on whether a temporary identifier for uplink communication has been set for said user equipment.

Preferably said method comprises receiving information at said user equipment via at least one of said first cell and at least one of said at least two further cells.

Preferably said method comprises monitoring said first identifier and said second identifier or monitoring said third identifier and said fourth identifier by said user equipment.

Preferably said information is transmitted between said first cell and said user equipment on a first carrier, and information is transmitted between at least one of said at least two further cells and said user equipment on a second carrier; or information is transmitted between said first cell and said user equipment and between said at least one of said at least two further cells and said user equipment on the same carrier.

Preferably said method comprises determining whether to transmit information via said first cell or said at least one further cell dependent on the load on said first cell and said at least one further cell.

Preferably at least one of said first, second, third and fourth identifiers are received at said user equipment from a Radio Network Controller. Preferably load information is received at said user equipment in one of: a System Information Block; a data header; dedicated signalling.

Preferably said first and second temporary identifiers comprise at least one of a High Speed Downlink Shared Channel Radio Network Temporary Identifier and an Enhanced Radio Network Temporary Identifier, and said third and fourth temporary identifiers comprise the other of a High Speed Downlink Shared Channel Radio Network Temporary Identifier and an Enhanced Radio Network Temporary Identifier.

In a second aspect there is provided a method comprising: setting a temporary identifier for identifying a user equipment located in a first area; and when said user equipment moves to a second area at least partially overlapping with said first area, providing information regarding the status of said identifier.

Preferably said first area comprises a macro-cell.

Preferably said second area comprises a small-cell.

Preferably said user equipment retains said temporary identifier when located in said second area.

Preferably said information indicates to a controller of said second area to use said temporary identifier without setting a new temporary identifier for said user equipment.

Preferably the method comprises sending uplink information from said user equipment in said second area on one of a Dedicated Control Channel and a Dedicated Traffic Channel.

Preferably said first area and said second area are comprised in a Forward Access Channel Registration Area. Preferably said user equipment retains said temporary identifier whilst said user equipment remains in said Forward Access Channel Registration Area.

Preferably the method comprises sending a cell update message from said user equipment only when said user equipment moves from said Forward Access Channel Registration Area to a second Forward Access Channel Registration Area.

Preferably said temporary identifier comprises an Enhanced Radio Network Temporary Identifier. Preferably said temporary identifier is received at said user equipment from a controller of the first area. Preferably the method comprises providing said information in a Media Access Control header. Preferably said information comprises a flag.

Preferably the temporary identifier for the first area is re-used by appending a flag when said user equipment wants to transact information to said second area. Preferably, upon receipt of a Media Access control header, a base station of the second area suppresses allocation of the temporary identifier for the second area.

Preferably the base station of the second area forwards the information from the user equipment to a radio network controller.

Preferably the base station of the second area memorizes the flag along with the temporary identifier.

Preferably the Radio Network Controller of the second area memorizes the flag along with the temporary identifier.

Preferably a base station of the second area uses the flag along with the temporary identifier to allocate resources to said user equipment on control channels. In a third aspect there is provided a method comprising: transmitting first and second temporary identifiers to a user equipment; wherein said first temporary identifier is associated with a first cell; and said second temporary identifier is associated with at least two further cells at least partially overlapping with said first cell. Preferably the method further comprises transmitting third and fourth temporary identifiers to said user equipment.

Preferably said first and second temporary identifiers are configured to enable one of downlink and uplink communication, and said third and fourth temporary identifiers are configured to enable the other of downlink and uplink communication. Preferably said first cell comprises a macro-cell and said at least two further cells comprise small-cells.

Preferably said first cell and said at least two further cells are comprised in a Forward Ac- cess Channel Registration Area.

Preferably the method comprises receiving a cell update message from said user equipment in order to allocate said temporary identifiers. Preferably the method comprises receiving information from said user equipment via said first cell or at least one of said two further cells, dependent on whether a temporary identifier for uplink communication has been set for said user equipment.

Preferably the method comprises transmitting information to said user equipment via at least one of said first cell and at least one of said at least two further cells.

Preferably the method comprises determining whether to transmit information via said first cell or said at least one further cell dependent on the load on said first cell and said at least one further cell.

Preferably at least one of said first, second, third and fourth identifiers are transmitted to said user equipment from a Radio Network Controller. Preferably load information is transmitted to said user equipment in one of: a System Information Block; a data header; dedicated signalling.

In a fourth aspect there is provided a method comprising: transmitting a temporary identifier for identifying a user equipment located in a first area; and when said user equipment moves to a second area at least partially overlapping with said first area, receiving information regarding the status of said identifier.

Preferably said first area comprises a macro-cell.

Preferably said second area comprises a small-cell.

Preferably the method comprises receiving uplink information from said user equipment in said second area on one of a Dedicated Control Channel and a Dedicated Traffic Channel.

Preferably the method comprises receiving a cell update message from said user equipment only when said user equipment moves from said Forward Access Channel Registration Area to a second Forward Access Channel Registration Area.

Preferably said temporary identifier comprises an Enhanced Radio Network Temporary Identifier. Preferably said temporary identifier is transmitted to said user equipment from a controller of the first area. Preferably the method comprises receiving said information in a Media Access Control header. Preferably said information comprises a flag.

Preferably a base station of the second area uses the flag along with the temporary identifier to allocate resources to said user equipment on control channels. In a fifth aspect there is provided a computer program comprising computer executable instructions which when run on one or more processors perform any of the methods as set forth above.

According to a sixth aspect there is provided an apparatus comprising: at least one proces- sor; and at least one memory including 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: set first and second temporary identifiers for said apparatus, wherein said first temporary identifier is associated with a first cell, and said second temporary identifier is associated with at least two further cells at least partially overlapping with said first cell. Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to set third and fourth temporary identifiers for said apparatus. Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to use said first and second temporary identifiers to enable one of downlink and uplink communication, and use said third and fourth temporary identifiers to enable the other of downlink and uplink communication. Preferably said first cell comprises a macro-cell and said at least two further cells comprise small-cells.

Preferably said first cell and said at least two further cells are comprised in a Forward Access Channel Registration Area.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to transmit a cell update message from said apparatus in order to obtain said temporary identifiers. Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to transmit information from said apparatus via said first cell or at least one of said two further cells, dependent on whether a temporary identifier for uplink communication has been set for said apparatus. Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to receive information via at least one of said first cell and at least one of said at least two further cells.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to monitor said first identifier and said second identifier, or monitor said third identifier and said fourth identifier.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to transmit information between said first cell and said apparatus on a first carrier, and transmit information between at least one of said at least two further cells and said apparatus on a second carrier; or transmit informa- tion between said first cell and said apparatus and between said at least one of said at least two further cells and said apparatus on the same carrier.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to determine whether to transmit information via said first cell or said at least one further cell dependent on the load on said first cell and said at least one further cell.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to receive at least one of said first, second, third and fourth identifiers from a Radio Network Controller.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to receive load information in one of: a System Information Block; a data header; dedicated signalling.

According to a seventh aspect there is provided an apparatus comprising at least one processor; and at least one memory including 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: set a temporary identifier for identifying said apparatus when located in a first area; and when said apparatus moves to a second area at least partially overlapping with said first area, provide information regarding the status of said identifier. Preferably said first area comprises a macro-cell.

Preferably said second area comprises a small-cell.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to retain said temporary identifier when located in said second area. Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to use said information to indicate to a controller of said second area to use said temporary identifier without setting a new tempo- rary identifier for said user equipment.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to send uplink information from said apparatus in said second area on one of a Dedicated Control Channel and a Dedicated Traf- fic Channel.

Preferably said first area and said second area are comprised in a Forward Access Channel Registration Area. Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to retain said temporary identifier whilst said apparatus remains in said Forward Access Channel Registration Area.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to send a cell update message from said user equipment only when said user equipment moves from said Forward Access Channel Registration Area to a second Forward Access Channel Registration Area.

Preferably said temporary identifier comprises an Enhanced Radio Network Temporary Iden- tifier.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to receive said temporary identifier from a controller of the first area.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to provide said information in a Media Access Control header. Preferably said information comprises a flag. According to an eighth aspect there is provided an apparatus comprising: at least one processor; and at least one memory including 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: transmit first and second temporary identifiers to a user equipment, wherein said first temporary identifier is associated with a first cell, and said second temporary identifier is associated with at least two further cells at least partially overlapping with said first cell.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to transmit third and fourth temporary identifiers to said user equipment.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to use said first and second tempo- rary identifiers to enable one of downlink and uplink communication, and to use said third and fourth temporary identifiers to enable the other of downlink and uplink communication.

Preferably said first cell comprises a macro-cell and said at least two further cells comprise small-cells.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to receive a cell update message from said user equipment in order to allocate said temporary identifiers.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to receive information from said user equipment via said first cell or at least one of said two further cells, dependent on whether a temporary identifier for uplink communication has been set for said user equipment.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to transmit information to said user equipment via at least one of said first cell and at least one of said at least two further cells. Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to transmit information between said first cell and said user equipment on a first carrier, and transmit information between at least one of said at least two further cells and said user equipment on a second carrier; or transmit information between said first cell and said user equipment and between said at least one of said at least two further cells and said user equipment on the same carrier.

Preferably at least one of said first, second, third and fourth identifiers are transmitted to said user equipment from a Radio Network Controller.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to transmit load information to said user equipment in one of: a System Information Block; a data header; dedicated signalling.

According to a ninth aspect there is provided an apparatus comprising at least one processor; and at least one memory including 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: transmit a temporary identifier for identifying a user equipment located in a first area; and when said user equipment moves to a second area at least partially overlapping with said first area, receive information regarding the status of said identifier.

Preferably said first area comprises a macro-cell.

Preferably said second area comprises a small-cell. Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to cause said user equipment to retain said temporary identifier when located in said second area.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to use said information to indicate to a controller of said second area to use said temporary identifier without setting a new temporary identifier for said user equipment.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to receive uplink information from said user equipment in said second area on one of a Dedicated Control Channel and a Dedicated Traffic Channel.

Preferably said first area and said second area are comprised in a Forward Access Channel Registration Area.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to cause said user equipment to retain said temporary identifier whilst said user equipment remains in said Forward Access Channel Registration Area.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to receive a cell update message from said user equipment only when said user equipment moves from said Forward Access Channel Registration Area to a second Forward Access Channel Registration Area.

Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to cause said temporary identifier to be transmitted to said user equipment from a controller of the first area. Preferably the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to receive said information in a Media Access Control header. Preferably said information comprises a flag.

According to a tenth aspect there is provided an apparatus comprising means for setting first and second temporary identifiers for said apparatus, wherein said first temporary identifier is associated with a first cell, and said second temporary identifier is associated with at least two further cells at least partially overlapping with said first cell.

Preferably the apparatus comprises means for setting third and fourth temporary identifiers for said apparatus. Preferably the apparatus comprises means for using said first and second temporary identifiers to enable one of downlink and uplink communication, and using said third and fourth temporary identifiers to enable the other of downlink and uplink communication.

Preferably said first cell and said at least two further cells are comprised in a Forward Access Channel Registration Area. Preferably the apparatus comprises means for transmitting a cell update message from said apparatus in order to obtain said temporary identifiers.

Preferably the apparatus comprises means for transmitting information from said apparatus via said first cell or at least one of said two further cells, dependent on whether a temporary identifier for uplink communication has been set for said apparatus.

Preferably the apparatus comprises means for receiving information via at least one of said first cell and at least one of said at least two further cells. Preferably the apparatus comprises means for monitoring said first identifier and said second identifier, or monitoring said third identifier and said fourth identifier. Preferably the apparatus comprises means for transmitting information between said first cell and said apparatus on a first carrier, and transmitting information between at least one of said at least two further cells and said apparatus on a second carrier; or transmitting infor- mation between said first cell and said apparatus and between said at least one of said at least two further cells and said apparatus on the same carrier.

Preferably the apparatus comprises means for determining whether to transmit information via said first cell or said at least one further cell dependent on the load on said first cell and said at least one further cell.

Preferably the apparatus comprises means for receiving at least one of said first, second, third and fourth identifiers from a Radio Network Controller. Preferably the apparatus comprises means for receiving load information in one of: a System Information Block; a data header; dedicated signalling.

According to an eleventh aspect there is provided an apparatus comprising means for set- ting a temporary identifier for identifying said apparatus when located in a first area; and means for providing information regarding the status of said identifier when said apparatus moves to a second area at least partially overlapping with said first area.

Preferably said first area comprises a macro-cell.

Preferably said second area comprises a small-cell.

Preferably the apparatus comprises means for retaining said temporary identifier when located in said second area. Preferably the apparatus comprises means for using said information to indicate to a controller of said second area to use said temporary identifier without setting a new temporary identifier for said user equipment. Preferably the apparatus comprises means for sending uplink information from said apparatus in said second area on one of a Dedicated Control Channel and a Dedicated Traffic Channel.

Preferably the apparatus comprises means for retaining said temporary identifier whilst said apparatus remains in said Forward Access Channel Registration Area. Preferably the apparatus comprises means for sending a cell update message from said user equipment only when said user equipment moves from said Forward Access Channel Registration Area to a second Forward Access Channel Registration Area.

Preferably the apparatus comprises means for receiving said temporary identifier from a controller of the first area. Preferably the apparatus comprises means for providing said information in a Media Access Control header.

Preferably said information comprises a flag. According to a twelfth aspect there is provided an apparatus comprising means for transmitting first and second temporary identifiers to a user equipment, wherein said first temporary identifier is associated with a first cell, and said second temporary identifier is associated with at least two further cells at least partially overlapping with said first cell.

Preferably the apparatus comprises means for transmitting third and fourth temporary identifiers to said user equipment. Preferably the apparatus comprises means for using said first and second temporary identifiers to enable one of downlink and uplink communication, and to use said third and fourth temporary identifiers to enable the other of downlink and uplink communication.

Preferably the apparatus comprises means for receiving a cell update message from said user equipment in order to allocate said temporary identifiers. Preferably the apparatus comprises means for receiving information from said user equipment via said first cell or at least one of said two further cells, dependent on whether a temporary identifier for uplink communication has been set for said user equipment.

Preferably the apparatus comprises means for transmitting information to said user equip- ment via at least one of said first cell and at least one of said at least two further cells.

Preferably the apparatus comprises means for transmitting information between said first cell and said user equipment on a first carrier, and transmitting information between at least one of said at least two further cells and said user equipment on a second carrier; or transmitting information between said first cell and said user equipment and between said at least one of said at least two further cells and said user equipment on the same carrier.

Preferably the apparatus comprises means for transmitting at least one of said first, second, third and fourth identifiers to said user equipment from a Radio Network Controller.

Preferably the apparatus comprises means for transmitting load information to said user equipment in one of: a System Information Block; a data header; dedicated signalling. Preferably said first and second temporary identifiers comprise at least one of a High Speed Downlink Shared Channel Radio Network Temporary Identifier and an Enhanced Radio Network Temporary Identifier, and said third and fourth temporary identifiers comprise the other of a High Speed Downlink Shared Channel Radio Network Temporary Identifier and an Enhanced Radio Network Temporary Identifier.

According to a thirteenth aspect there is provided an apparatus comprising means for transmitting a temporary identifier for identifying a user equipment located in a first area; and means for receiving information regarding the status of said identifier when said user equipment moves to a second area at least partially overlapping with said first area.

Preferably said first area comprises a macro-cell. Preferably said second area comprises a small-cell.

Preferably the apparatus comprises means for retaining said temporary identifier when located in said second area. Preferably the apparatus comprises means for using said information to indicate to a controller of said second area to use said temporary identifier without setting a new temporary identifier for said user equipment.

Preferably the apparatus comprises means for receiving uplink information from said user equipment in said second area on one of a Dedicated Control Channel and a Dedicated Traffic Channel.

Preferably the apparatus comprises means for retaining said temporary identifier whilst said user equipment remains in said Forward Access Channel Registration Area.

Preferably the apparatus comprises means for receiving a cell update message from said user equipment only when said user equipment moves from said Forward Access Channel Registration Area to a second Forward Access Channel Registration Area. Preferably said temporary identifier comprises an Enhanced Radio Network Temporary Identifier. Preferably the apparatus comprises means for transmitting said temporary identifier to said user equipment from a controller of the first area.

Preferably the apparatus comprises means for receiving said information in a Media Access Control header.

Preferably said information comprises a flag.

Some embodiments will now be explained with reference to the appended Figures in which: Figure 1 shows a schematic diagram of a network according to some embodiments;

Figure 2 shows a schematic diagram of a mobile communication device according to some embodiments;

Figure 3 shows a schematic diagram of a control apparatus according to some embodiments;

Figure 4 shows a macro-only network and a heterogeneous network;

Figure 5 shows the movement of a user equipment between pico and/or macro cells according to some embodiments;

Figure 6 shows the signalling between various entities according to an embodiment;

Figure 7 shows the signalling between various entities according to an embodiment; Figure 8 shows the signalling between various entities according to an embodiment.

In the following certain exemplifying embodiments are explained with reference to a wireless or mobile communication system serving mobile communication devices. Before explaining in detail the exemplifying embodiments, certain general principles of a wireless communica- tion system and mobile communication devices are briefly explained with reference to Figures 1 to 3 to assist in understanding the technology underlying the described examples.

In a wireless communication system mobile communication devices or user equipments (UE) 102, 103, 105 are provided wireless access via at least one base station or similar wire- less transmitting and/or receiving node or point. In the Figure 1 example two overlapping access systems or radio service areas of a cellular system 100 and 1 10 and three smaller ra- dio service areas 1 15, 1 17 and 1 19 provided by base stations 106, 107, 1 16, 1 18 and 120 are shown. Each mobile communication device and station may have one or more radio channels open at the same time and may send signals to and/or receive signals from more than one source. It is noted that the radio service area borders or edges are schematically shown for illustration purposes only in Figure 1. It shall also be understood that the sizes and shapes of radio service areas may vary considerably from the shapes of Figure 1. A base station site can provide one or more cells. A base station can also provide a plurality of sectors, for example three radio sectors, each sector providing a cell or a subarea of a cell. All sectors within a cell can be served by the same base station.

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. In Figure 1 control apparatus 108 and 109 is shown to control the respective macro level base stations 106 and 107. The control apparatus of a base sta- tion 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. The control apparatus 108 may be part of the base station or it may be physically separate from the base station. The control apparatus 108 may serve a plurality of macro and/or pico cells. The control appara- tus may for example be a radio network controller (RNC).

In Figure 1 stations 106 and 107 are shown as connected to a wider communications network 1 13 via gateway 1 12. Gateway 1 12 may for example be a Gateway General Packet Radio Service Support Node (GGSN). A further gateway function may be provided to con- nect to another network. The smaller stations 1 16, 1 18 and 120 can 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. 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. Gateway 1 1 1 may for example be a Serving General Packet Radio Service Support Node (SGSN).

A possible mobile communication device for transmitting and retransmitting information blocks towards the stations of the system will now be described in more detail in reference to Figure 2 showing a schematic, partially sectioned view of a communication device 102. Such a communication device is often referred to as user equipment (UE) or terminal. An appro- priate mobile communication device may be provided by any device capable of sending and receiving radio signals. Non-limiting examples include a mobile station (MS) such as a mo- bile phone or what is known as a 'smart phone', a computer provided with a wireless interface card or other wireless interface facility, personal data assistant (PDA) 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 com- munications 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 include 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 include downloads, television and radio programs, videos, advertisements, various alerts and other information. The mobile device 102 may receive signals over an air 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 pro- vided 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 wireless communication device can be provided with a Multiple Input / Multiple Output (MIMO) antenna system. MIMO arrangements as such are known. MIMO systems use mul- tiple antennas at the transmitter and receiver along with advanced digital signal processing to improve link quality and capacity. Although not shown in Figures 1 and 2, multiple antennas can be provided, for example at base stations and mobile stations, and the transceiver apparatus 206 of Figure 2 can provide a plurality of antenna ports. More data can be received and/or sent where there are more antenna elements. A station may comprise an ar- ray of multiple antennas. Signalling and muting patterns can be associated with Tx antenna numbers or port numbers of MIMO arrangements.

A mobile device is also 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 communica- tion device may comprise appropriate connectors (either wired or wireless) to other devices and/or for connecting external accessories, for example hands-free equipment, thereto.

Figure 3 shows an example of a control apparatus for a communication system, for example to be coupled to and/or for controlling a station of an access system, such as a base station. In some embodiments base stations comprise a separate control apparatus. In other embodiments the control apparatus can be another network element. The control apparatus 109 can be arranged to provide control on communications in the service area of the system. The control apparatus 109 can be configured to provide control functions in association with generation and communication of request and instructions in view of reception of information blocks, retransmissions and other related information by means of the data processing facility in accordance with certain embodiments described below. For this purpose the control apparatus 109 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 cou- pled to a receiver and a transmitter of the base station. The control apparatus 109 can be configured to execute an appropriate software code to provide the control functions. It shall be appreciated that similar component can be provided in a control apparatus provided elsewhere in the system for controlling reception of sufficient information for decoding of received information blocks.

The communication devices 102, 103, 105 can access the communication system based on various access techniques, such as code division multiple access (CDMA), or wideband CDMA (WCDMA). Other examples include time division multiple access (TDMA), frequency division multiple access (FDMA) and various schemes thereof such as the interleaved fre- quency division multiple access (IFDMA), single carrier frequency division multiple access (SC-FDMA) and orthogonal frequency division multiple access (OFDMA), space division multiple access (SDMA) and so on.

Figure 4 schematically shows two macro-cells 400 and 410.

On the left hand side of Figure 4 user equipment 402 is moving within macro-cell 400 in the direction of arrow A. During this movement the user equipment 402 remains within macro- cell 400. Therefore the UE 402 does not need to send a CELL_UPDATE message due to cell reselection.

As discussed above, communication systems may comprise pico or micro-cells or other "small cells". Herafter the term small-cell is used to refer generally to pico and/or micro-cells, or any other "small cell". Likewise the terms "pico" and "micro" cell may be used generally to refer to any type of small cell. Communication systems may comprise a combination of macro and small-cells. Such radio access networks may be referred to as heterogeneous networks or "hetnets".

An example of a hetnet is shown on the right-hand side of Figure 4. This hetnet comprises a macro-cell 410, within which small-cells 422, 424, 426 and 428 are located. As the user equipment 403 moves in the direction of arrow B it passes from small cell 422 to small-cell 424 to small-cell 426 to small-cell 428. Each time the UE 403 moves from one small-cell to another it sends an update message (CELLJJPDATE) to the network to inform the network that a cell change has occurred (i.e. due to cell reselection). The macro-cell 410 may be considered a Forward Access CHannel Registration Area (FRA) i.e. each of small-cells 422, 424, 426 and 428 are considered to belong to the same FRA.

It should be appreciated that Figure 4 is exemplary in nature and that the interaction of small-cells with macro cells can differ. For example a cluster of small-cells may be fully contained within a macro-cell. Alternatively some cells within the cluster may be within a macro- cell whilst other small-cells of the cluster may overlap with or be outside of the macro-cell. Alternatively a cluster of small-cells may have no interaction with a macro-cell.

In practice the majority of hetnet users are smart phones, tablets and/or other devices which are kept in an "always on" state. To remain in the "always on" state the UE broadcasts a "keep alive" message once every 2 to 10 minutes. The transmission of "keep alive" mes- sages typically requires a signalling transaction (a Cell Update procedure to refresh the UE identifiers required for data transmission) before the actual data transmission happens. This enables the UE to maintain its "always on" impression whilst saving battery life at the same time. Due to the introduction of small cells (with macro-cells offering overlaying coverage) the number of "cell update" RRC messages may become very high due to the increased number of cell reselections in the CELL_FACH state. This may result in control plane overload and requires frequent and elaborate dimensioning exercises every time small cells are deployed. One option for avoiding the cell update to be triggered whenever a UE moves between two cells belonging to the same URA area (UTRAN registration area) is to put the UE into a URA_PCH state. The URA_PCH state is a connected mode defined since 3GPP Rel'99. A drawback of configuring UEs with the URA_PCH state is that this state supports limited HS- FACH/HS-RACH function compared with CELL_PCH or CELL_FACH states. In URA_PCH state the HS-DSCH (high speed downlink shared channel) is used to enable reception of PCCH (paging control channel) logical channel data. The URA_PCH state is therefore not the optimum state for the UE to use the HS-FACH/HS- RACH feature which is most likely to be used by smartphones in their "always on" mode of operation used widely in densely populated areas. Furthermore, if a UE in the URA_PCH state receives downlink data or sends uplink data, then the UE has to first transfer to the CELL_FACH state. Once in the CELL_FACH state the UE will once again send cell update messages when moving between small-cells within a URA. This may result in an increased number of update messages being sent, as discussed in above sections.

Hence, in the given context, the URA_PCH state may not be optimal for enabling terminals quick access to fast common data channels whilst also limiting the number of cell update procedures. UL transmission of HS-RACH by a UE using common E-DCH (enhanced dedicated channel) is shown in 3GPP Rel8. However whenever a HS-RACH capable UE enters a new cell, it cannot immediately start UL transmission without having to first go through a cell update procedure in which temporary radio network identifiers (RNTI) are issued by the controlling RNC of the cell.

One embodiment may enable the number of signalling messages to be reduced in a hetnet scenario for a UE in a connected mode (CELL_PCH or CELL_FACH). In the embodiment the macro cell may be deployed on a first carrier f1 and all small cells may be deployed on a second carrier f2. Alternatively the macro cells and small cells may be deployed with the same carrier. In an embodiment the small cells and the macro cells connect to the same RNC and all small cells are placed under the coverage of a macro cell. There may be a plurality of macro cells each providing coverage for one or more small cells. A UE under a small cell coverage may also be simultaneously under a macro cell's coverage. Accordingly in some embodiments the UE has the capability to monitor two or more cells at the same time e.g. one or more small cells and one or more macro cells. As discussed above with respect to Figure 4, several small cells may belong to one FRA and there could be more than one FRA contained by the coverage area of a macro cell.

Thus a UE in a connected mode (for example CELL_FACH or CELL_PCH) may not need to initiate cell update messages when moving between small cells belonging to the same FRA, but may initiate a cell update when moving between two FRAs.

In some embodiments a new Enhanced Radio Network Temporary Identifier (E-RNTI) and assignment and usage thereof is proposed. As will be discussed in more detail below in some embodiments the new E-RNTI may not be reset every time a UE reselects to a cell, but rather may stay the same while moving along cells belonging to the same FRA.

The following terms are used in some embodiments to represent the H-RNTI/E-RNTI which is used in the macro cell or small cell. · P-H-RNTI (pico H - RNTI) is allocated by the RNC. This identifier may be used by a

UE to receive DL data in pico/small cells. The P-H-RNTI is shared in one FRA which includes one or more small cells. Thus a UE moving within an FRA may not need to change the P-H-RNTI. · M-H-RNTI (macro H-RNTI) is allocated by the RNC to one or more user equipment.

This may be used by a UE to receive DL data in a macro cell

• P-E-RNTI (pico E-RNTI) is allocated by one pico/small node. This identifier is used in one working small cell

• M-E-RNTI (macro E-RNTI) is allocated by a macro node B, and is used in a macro cell.

The terms P-H-RNTI, M-H-RNTI, P-E-RNTI, M-E-RNTI are an example of terms that may be used to refer to an identifier having the described functionality. In other embodiments they may be named differently.

Thus according to some embodiments a UE in the connected mode (CELL_FACH or CELL_PCH) may have two H-RNTIs assigned by the RNC: one being the M-H-RNTI for the macro cell and the other being the P-H-RNTI for the small cell. A UE in such a connected mode may be configured to monitor for these two identifiers simultaneously. A UE in this connected mode may have one M-E-RNTI for a macro cell assigned by a macro-NodeB, which can be used to send uplink data transmission in the macro cell as legacy HS-RACH.

In some embodiments if DL data arrives at the RNC, with the intention to reach a UE in the downlink, since there are two H-RNTIs stored in the UE then the RNC and associated Node-Bs can send HS-SCCH/HS-DSCH data to the UE from the macro cell, or from the small cells, or from both cells. When data is received at a UE from a macro cell or from one small cell then the UE can perform UL feedback to one of the Node-Bs from the working cells that the data has been received. This acknowledgement may be in the form of ACK messages.

If a UE has received the same downlink data from both a macro cell and a small cell simultaneously, then in some embodiments the UE can select one of the two cells to do the UL feedback to. In other embodiments the UE can feedback to both the macro cell and the small cell.

In some embodiments the UE can determine or be instructed whether to receive DL data from a macro cell or from a small cell. For example a UE may receive DL data from a macro cell by M-H-RNTI. However the UE can decide to select a camped small cell to continue subsequent DL/UL data receipt/transmission, using P-H-RNTI for subsequent DL data receipt. This may be desirable for example for load balancing or so that the UE can obtain more resources. In such an embodiment the UE can send the cell updates directly to the small node B to apply P-E-RNTI assignment by cell update confirm message. Likewise if the UE receives DL data from the small cell by P-H-RNTI, the UE may select a macro cell to continue subsequent UL/DL data receipt/transmission by sending cell update to the macro cell. Again this may be for reasons such as load balancing or to obtain more resources. When UL data arrives at a UE, as it might have one M-E-RNTI assigned by the macro Node-B, the UE can select a cell for the UL data transmission based on a load balance situation or network instruction. If the M-E-RNTI has been stored, the UE can send UL data to the macro Node-B directly (as per legacy 3GPP Rel-8 HS-RACH). Alternatively the UE can send CELL UPDATE message to the small Node-B to apply P-E-RNTI by CELL UP- DATE CONFIRM from the small NodeB. In some embodiments, when a UE has two H-RNTIs and two E-RNTIs stored, the RNC can receive data from either the macro cell or the working (current) small cell and may transmit data on either the macro cell or the working (current) small cell. Relationship information that a small cell is matching/associated with one macro cell can be, in some embodiments, broadcast in System Information Blocks (SIBs) of each small or macro cell. This information can be used by the UE to determine which small cells within a macro cell the UE needs to monitor. Alternatively this information regarding the relationship of a small cell to a macro cell can be indicated to a UE by a new extension within the dedi- cated Neighbour Cell List (NCL) provided to the UE from the network. In this situation the Physical Scrambling Code (PSC) entries corresponding to small cell may be distinguished from each other, for example by adding an indicator or setting an extra bit etc. Using this extension the UE can store this information and react upon entering a small cell. Load balancing between a macro cell and a small cell using two H-RNTIs may comprise load balancing with network assistance. For example a UE may get overload indication of a macro or small cell from the cell's SIBs, or from Medium Access Controller MAC-hs/MAC- ehs Protocol Data Unit (PDU)header, or from control Radio Link Control (RLC) PDU, or may be informed by dedicated signalling for previous state transition. This indication may help a UE know the overload situation of a cell, then select a suitable (possibly different) cell to do the UL sending.

Relationship information that a pico cell is matching or associated with one macro cell can be broadcast in SIB, or be an extension of NCL, or a new indication/extra bit in PSC.

Alternatively some embodiments may use network controlled load balance. In such an embodiment the UE may randomly select one cell to send a cell update to. If the Node-B/cell which receives the UL message is overloaded but another Node-B/cell is free, the RNC can send CELL UPDATE CONFIRM from another Node-B/cell to the UE. As a result, the UE may select the Node-B/cell which sent this DL message to continue subsequent DL/UL data reception/transmission.

For load balancing, in some embodiments the RNC can switch (hijack) the UE selected cell to another cell, and for DL transmission the UE can apply identity from another cell to switch(hijack) RNC selected cell to another cell. The principles described above which are intended to reduce CELL UPDATE transmission in UL are further explained with reference to Figure 5. Figure 5 shows multiple mobility scenarios. Figure 5 shows a first macro cell 1 , and at least partially within the coverage area of macro cell 1 are pico cells 1.1 , 1.2, 1 .3 and 1.4.

Figure 5 also shows a second macro cell 2, and at least partially within the coverage area of macro cell 2 are pico cells 2.1 , 2.2, 2.3 and 2.4.

In a first mobility scenario shown by the shaded arrows a UE 102 enters macro cell 1 (macro-cell on left hand side of Figure 5), then traverses a path to pico cell 1.3, to pico cell 1.4 and then to pico cell 1 .1. Initially the UE sets a 1 -bit flag to indicate that the UE is currently receiving allocation of M- E-RNTI in the macro cell. This may be indicated in the MAC-i header on the uplink. This flag may be an additional bit which acts as a sign extension bit which effectively doubles the addressing range of the existing 16 bits of the M-E-RNTI. When the UE moves from macro cell 1 to pico cell 1 .3 and wants to send UL data in the pico cell, the UE can use DCCH/DTCH transmission to a base station of the pico cell directly without requiring CCCH transmission first. At this stage the UE in CELL_PCH and CELL_FACH would not have the P-E-RNTI allocated by the pico cell (it is assumed here that the pico cell 1 .3 is the 1 ^st small cell entered by the UE within macro cell 1 ).

The UE then sets the flag in the Mac-i header to "1 ". Accordingly when a pico base station checks the flag and determines that it is set to 1 it does not allocate the P-E-RNTI from the pico cell to the UE but simply forwards the transmitted PDU (DTCH/DCCH) to the RNC via a legacy E-DCH data frame (Frame Protocol). The M-E-RNTI allocated flag is also passed onto the RNC in E-DCH data frame (Frame Protocol).

The legacy collision resolution procedure for a small base station to grant a common E-DCH resource may be enhanced by either adding M-E-RNTI allocated bit to the legacy downlink enhanced access grant channel (E-AGCH) or by reusing one bit from the legacy downlink E-AGCH channel. Preferably the small base station memorises the allocated M-E-RNTI along with the flag to distinguish E-RNTI allocation. This enables the small cell to distinguish over identifiers that have been allocated to other UEs. Preferably the RNC also memorises M-E-RNTI along with the flag (proposed above) so as to distinguish UEs in the CELL_FACH state in the lub user plane.

A second mobility scenario is shown by a user equipment moving in the path of the hatched arrows. In this scenario the UE enters into RRC connected mode by camping initially to pico cell 1.2. In this case the UE follows a path entering pico cell 1 .2, then "moves to" macro cell 1 (see next sentence) to small cell 1 .1 . Even in the case where the UE is always within coverage area of macro cell 1 , it may not be necessarily binding on the UE to access both the macro cell and one or more pico cells at same time, e.g. this could be a choice on the UE settings from end user etc. Therefore in this particular case the UE has to perform only one cell update when it reselects to macro cell 1 from pico cell 1 .2. Following this cell update the case becomes the same as the first mobility scenario shown by the shaded arrows.

A third mobility scenario is shown by the cross-hatched arrow in Figure 5. In this scenario the UE traverses a path from pico cell 1 .4 to macro cell 2. In this situation the UE has to per- form a cell update when it reselects to macro cell 2.

The table below summarises scenarios where the user equipment starts and then remains in either a macro or small cell, and the expected handling in each case.

Table 1 The flow diagram of Figure 6 shows exemplary signalling between UE 102, small BTS 120, macro BTS 106, RNC 108 and CN 1 13 according to some embodiments.

As shown at step 1 of the signalling the UE 102 is configured for dual frequency reception. The UE 102 has also set up a Radio Access Bearer (RAB) via the macro BTS 106. The UE 102 is also configured in the CELL_FACH state.

At step 1 the RNC 108 assigns the M-H-RNTI (on carrier f1 ) and the P-H-RNTI (on carrier f2), whereas discussed above f1 and f2 may be separate carriers. The M-E-RNTI (f1 ) is assigned to the UE 102 by the macro-BTS 106. As shown at step 2 the packet data is then sent from the core network 1 13 to the RNC 108. Once the RNC 108 receives the packet data it is sent, along with the identifier M-H-RNTI, onto the macro BTS 106 and subsequently to the UE 102. The UE 102 analyses the SIB for the small and macro cell association and it listens to the f2 carrier to monitor for small cells. At step 3 the UE 102 moves cells and accordingly sends a cell update message on the common E-DCH to the small BTS 120. At step 4 the small BTS 120 allocates a P-E-RNTI for the UE 102 in the small cell. The small BTS 120 then forwards this information on an E-DCH Frame Type 2 message to the RNC 108 at step 5. This provides the RNC 108 with an activation point for the small f2 carrier.

At step 6 a Cell Update Confirm message is sent to the UE 102 via M-H-RNTI or P-H-RNTI. Alternatively this Cell Update Confirm message may be sent on both M-H-RNTI and the P- H-RNTI. As shown at step 7 the RNC is thus capable of receiving data from either the f1 or f2 carrier and may also transmit data on the f1 or f2 carrier. This is demonstrated in steps 8 and 9.

At step 8 packet data X is sent from CN 1 13 to RNC 108. From the RNC 108 the packet data X is transmitted to macro BTS 106 with M-H-RNTI. The packet data X is then for- warded from the macro BTS 106 to the UE 102 with the M-H-RNTI.

At step 9 packet data Y is transmitted from CN 1 13 to RNC 108. At RNC 108 the P-H-RNTI is assigned and the packet data Y is forwarded to the pico BTS 120 with this identifier. From pico BTS 120 the packet data Y is forwarded to UE 102 with the identifier P-H-RNTI.

As stated at the bottom of Figure 6 by the end of this procedure the RNC is able to load balance the HS-FACH/HS-RACH on the DL/UL. Furthermore the cell FACH can be offloaded for the UE to pico/small f2 carrier. The RNC 108 and UE 102 may also use any of the frequencies allocated for transmission and reception.

Figure 7 is a flow diagram showing exemplary signalling between a UE 702, pico BTS 720, macro BTS 706, RNC 708 and CN 713. The signalling in Figure 7 is applicable to the first mobility scenario shown by the shaded arrows in Figure 5. At step one of Figure 7 the UE 702 has camped to macro BTS 706. The user equipment is in a cell FACH state, and the RNC 708 assigned the M-H-RNTI and the P-H-RNTI. Only the M-E-RNTI (f 1 ) is assigned to the UE 702 by the macro BTS 706.

The user equipment 702 then moves into a pico cell (e.g. pico cell 1 .3 as per Figure 5). The UE 702 reuses the M-E-RNTI that was assigned by the macro BTS 706, when the UE 702 is in the pico cell (e.g. pico cell 1.3). At step 2 the UE 702 has entered the pico cell and wants to transmit data on the uplink.

As shown at step 3, to enable this the UE 702 accesses the common E-DCH resource with the M-E-RNTI. The UE 702 sets a one bit flag in the MAC-i PDU to 1 to indicate that the UE 702 is currently receiving allocation of M-E-RNTI in the macro cell (i.e. M-E-RNTI allocated = TRUE).

Accordingly as shown at step 4 the pico BTS 720 does not allocate the P-E-RNTI for this UE.

As shown at step 5 the pico BTS 720 then memorises this information, including committing the M-E-RNTI allocated bit and M-E-RNTI to the memory for future use. As shown at step 6 this information is then sent from the pico BTS 722 to the RNC 708.

The collision resolution procedure is shown at steps 7 to 1 1. Firstly, at step 7 the M-E-RNTI allocated bit is added to the downlink enhanced access grant channel (E-AGCH). As shown at step 8 the UE 702 then stops using the M-E-RNTI in the MAC-i PDU, and at step 9 the RNC memorises the information including committing M-E-RNTI allocated bit and M-E-RNTI to memory for future use. As shown at step 10 an uplink packet is sent from the RNC 708 to the CN 730. This packet may contain uplink application data sent by the UE application which needs to be forwarded towards the packet core. As shown at step 1 1 the UE 702 may then continue transferring additional data on the granted common E-DCH, as long as it has access to the physical resource based on legacy handling.

As shown at step 12 the pico BTS 720 can now send uplink data to the RNC 708 based on the memorised information.

The flow diagram of Figure 8 shows exemplary signalling between UE 802, pico BTS 820, macro BTS 806, and RNC 808 according to an embodiment. The steps of Figure 8 are applicable to the second mobility scenario shown by the hatched arrows in Figure 5. As shown at step 1 of Figure 8 the UE has camped to pico BTS 820 and wants to establish an RRC connection. During a legacy RRC connection setup procedure, the RNC 808 assigns P-H-RNTI and the pico BTS assigns the P-E-RNTI. The UE 802 then wants to access a macro cell (e.g. macro-cell 1 as shown in Figure 5). The UE 802 performs a cell update to the macro cell.

As shown at step 2 the UE then performs an RRC connection from within the pico cell (e.g. pico cell 1 .2 as shown in Figure 5).

As shown at step 3 the UE then accesses the common E-DCH without an E-RNTI using a CCCH: RRC Connection Request.

At step 4 the pico BTS 820 allocates the P-E-RNTI for the UE 802.

As shown at step 5 the MAC-i PDUs and P-E-RNTI are sent from the pico BTS 820 to the RNC 808 using E-DCH Frame Type 2 signalling.

Step 6 shows the RRC connection setup procedure. The UE 802 is in the cell FACH state and the RAB is setup. The RNC 808 can then allocate the P-E-RNTI.

Following this, at step 7, it is shown that the UE 802 now has the P-E-RNTI and the P-H- RNTI. The UE 802 can also use the high speed RACH and FACH channels. Steps 8 to 10 show the procedure when the UE 802 wants to select the macro cell (e.g. macro cell 1 shown in Figure 5). At step 9, using the common E-DCH resource the UE 802 sends a CCCH: Cell Update message to the pico BTS 820. This message is subsequently forwarded on from the pico BTS 820 to the RNC 808 along with the MAC-is PDUs and P-E- RNTI.

At step 10 the RNC 808 sends a cell update confirm message to the UE 802, along with an M-H-RNTI and M-E-RNTI (i.e. the identifiers for the macro cell).

At step 1 1 the RNC 808 sends a UE status update command to the pico BTS 820 informing the pico BTS 820 to release the P-E-RNTI. As shown at step 12 the UE 802 can now move across pico cells without having to apply for another P-E-RNTI.

As discussed above some embodiments may reduce the number of signalling messages due to the reduced number of cell update messages required in a hetnet scenario for a UE in a CELL_PCH or CELL_FACH connected mode. Accordingly the UE battery life may also be improved and the network signalling load is reduced by saving the cell update procedure execution time in the RNC and the UE. Transmission resources on the lub and air interface may also be saved which reduces common channel congestion. In some embodiments this is achieved by the E-RNTI being assigned only once (at the beginning of the RRC connec- tion procedure) by the anchoring macro cell. When a UE moves to other small cells within an FRA the UE can indicate the E-RNTI together with the flag in the MAC-i header to the small cells, which can allow them to re-use this identity (E-RNTI) without issuing a new one. The UE can then send uplink data using the DTCH/DCCH channels without using the slower CCCH and triggering the cell update procedure. According to this principle UL delay associ- ated with establishing a new UL UE context in the new cell may be mitigated since the small cells will be reusing the existing UE EL stored in the macro cell.

An appropriately adapted computer program code product or products may be used for implementing the embodiments, when loaded on an appropriate data processing apparatus, for example for determining geographical boundary based operations and/or other control operations. The program code product for providing the operation may be stored on, provided and embodied by means of an appropriate carrier medium. An appropriate computer program can be embodied on a computer readable record medium. A possibility is to download the program code product via a data network. In general, the various embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Embodiments of the inventions may thus 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 semi- conductor substrate.

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

Claims

1. A method comprising:

setting first and second temporary identifiers for a user equipment;

wherein said first temporary identifier is associated with a first cell;

and said second temporary identifier is associated with at least two further cells at least partially overlapping with said first cell.

2. A method as set forth in claim 1 , further comprising setting third and fourth temporary identifiers for said user equipment.

3. A method as set forth in claim 2, wherein said first and second temporary identifiers are configured to enable one of downlink and uplink communication, and said third and fourth temporary identifiers are configured to enable the other of downlink and uplink com- munication.

4. A method as set forth in any preceding claim, wherein said first cell comprises a macro-cell and said at least two further cells comprise small-cells.

5. A method as set forth in any preceding claim, wherein said first cell and said at least two further cells are comprised in a Forward Access Channel Registration Area.

6. A method as set forth in any preceding claim, comprising transmitting a cell update message from said user equipment in order to obtain said temporary identifiers.

7. A method as set forth in any preceding claim, comprising transmitting information from said user equipment via said first cell or at least one of said two further cells, dependent on whether a temporary identifier for uplink communication has been set for said user equipment.

8. A method as set forth in any preceding claim, comprising receiving information at said user equipment via at least one of said first cell and at least one of said at least two further cells.

9. A method as set forth in claim 2, comprising monitoring said first identifier and said second identifier or monitoring said third identifier and said fourth identifier by said user equipment.

10. A method as set forth in any preceding claim, wherein information is transmitted between said first cell and said user equipment on a first carrier, and information is transmitted between at least one of said at least two further cells and said user equipment on a second carrier; or information is transmitted between said first cell and said user equipment and between said at least one of said at least two further cells and said user equipment on the same carrier.

1 1 . A method as set forth in any preceding claim, comprising determining whether to transmit information via said first cell or said at least one further cell dependent on the load on said first cell and said at least one further cell.

12. A method as set forth in claim 2, wherein at least one of said first, second, third and fourth identifiers are received at said user equipment from a Radio Network Controller.

13. A method as set forth in any preceding claim, wherein load information is received at said user equipment in one of: a System Information Block; a data header; dedicated signalling.

14. A method as set forth in claim 2, wherein said first and second temporary identifiers comprise at least one of a High Speed Downlink Shared Channel Radio Network Temporary Identifier and an Enhanced Radio Network Temporary Identifier, and said third and fourth temporary identifiers comprise the other of a High Speed Downlink Shared Channel Radio Network Temporary Identifier and an Enhanced Radio Network Temporary Identifier.

15. A method comprising:

setting a temporary identifier for identifying a user equipment located in a first area; and when said user equipment moves to a second area at least partially overlapping with said first area, providing information regarding the status of said identifier.

16. A method as set forth in claim 15, wherein said first area comprises a macro-cell.

17. A method as set forth in claim 15 or claim 16, wherein said second area comprises a small-cell.

18. A method as set forth in any of claims 15 to 17, wherein said user equipment retains said temporary identifier when located in said second area.

19. A method as set forth in any of claims 15 to 18, wherein said information indicates to a controller of said second area to use said temporary identifier without setting a new temporary identifier for said user equipment.

20. A method as set forth in any of claims 15 to19, comprising sending uplink information from said user equipment in said second area on one of a Dedicated Control Channel and a Dedicated Traffic Channel.

21 . A method as set forth in any of claims 15 to 20, wherein said first area and said second area are comprised in a Forward Access Channel Registration Area.

22. A method as set forth in claim 21 , wherein said user equipment retains said temporary identifier whilst said user equipment remains in said Forward Access Channel Registra- tion Area.

23. A method as set forth in claim 21 or claim 22, comprising sending a cell update message from said user equipment only when said user equipment moves from said Forward Access Channel Registration Area to a second Forward Access Channel Registration Area.

24. A method as set forth in any of claims 15 to 23, wherein said temporary identifier comprises an Enhanced Radio Network Temporary Identifier.

25. A method as set forth in any of claims 15 to 24, wherein said temporary identifier is received at said user equipment from a controller of the first area.

26. A method as set forth in any of claims 15 to 25, comprising providing said information in a Media Access Control header.

27. A method as set forth in any of claims 15 to 26, wherein said information comprises a flag.

28. A method comprising:

transmitting first and second temporary identifiers to a user equipment;

wherein said first temporary identifier is associated with a first cell;

29. A method as set forth in claim 28, further comprising transmitting third and fourth temporary identifiers to said user equipment.

30. A method as set forth in claim 29, wherein said first and second temporary identifiers are configured to enable one of downlink and uplink communication, and said third and fourth temporary identifiers are configured to enable the other of downlink and uplink communication.

31 . A method as set forth in any of claims 28 to 30, wherein said first cell comprises a macro-cell and said at least two further cells comprise small-cells.

32. A method as set forth in any of claims 28 to 31 , wherein said first cell and said at least two further cells are comprised in a Forward Access Channel Registration Area.

33. A method as set forth in any of claims 28 to 32, comprising receiving a cell update message from said user equipment in order to allocate said temporary identifiers.

34. A method as set forth in any of claims 28 to 33, comprising receiving information from said user equipment via said first cell or at least one of said two further cells, dependent on whether a temporary identifier for uplink communication has been set for said user equipment.

35. A method as set forth in any of claims 28 to 34, comprising transmitting information to said user equipment via at least one of said first cell and at least one of said at least two further cells.

36. A method as set forth in any of claims 28 to 35, wherein information is transmitted between said first cell and said user equipment on a first carrier, and information is transmitted between at least one of said at least two further cells and said user equipment on a sec- ond carrier; or information is transmitted between said first cell and said user equipment and between said at least one of said at least two further cells and said user equipment on the same carrier.

37. A method as set forth in any of claims 28 to 36, comprising determining whether to transmit information via said first cell or said at least one further cell dependent on the load on said first cell and said at least one further cell.

38. A method as set forth in claim 29, wherein at least one of said first, second, third and fourth identifiers are transmitted to said user equipment from a Radio Network Controller.

39. A method as set forth in any of claims 28 to 38, wherein load information is transmitted to said user equipment in one of: a System Information Block; a data header; dedicated signalling.

40. A method as set forth in claim 29, wherein said first and second temporary identifiers comprise at least one of a High Speed Downlink Shared Channel Radio Network Temporary Identifier and an Enhanced Radio Network Temporary Identifier, and said third and fourth temporary identifiers comprise the other of a High Speed Downlink Shared Channel Radio Network Temporary Identifier and an Enhanced Radio Network Temporary Identifier.

41 . A method comprising:

transmitting a temporary identifier for identifying a user equipment located in a first area; and when said user equipment moves to a second area at least partially overlapping with said first area, receiving information regarding the status of said identifier.

42. A method as set forth in claim 41 , wherein said first area comprises a macro-cell.

43. A method as set forth in claim 41 or claim 42, wherein said second area comprises a small-cell.

44. A method as set forth in any of claims 41 to 43, wherein said user equipment retains said temporary identifier when located in said second area.

45. A method as set forth in any of claims 41 to 44, wherein said information indicates to a controller of said second area to use said temporary identifier without setting a new temporary identifier for said user equipment.

46. A method as set forth in any of claims 41 to 45, comprising receiving uplink information from said user equipment in said second area on one of a Dedicated Control Channel and a Dedicated Traffic Channel.

47. A method as set forth in any of claims 41 to 46, wherein said first area and said sec- ond area are comprised in a Forward Access Channel Registration Area.

48. A method as set forth in claim 47, wherein said user equipment retains said temporary identifier whilst said user equipment remains in said Forward Access Channel Registration Area.

49. A method as set forth in claim 47 or claim 48, comprising receiving a cell update message from said user equipment only when said user equipment moves from said Forward Access Channel Registration Area to a second Forward Access Channel Registration Area.

50. A method as set forth in any of claims 41 to 49, wherein said temporary identifier comprises an Enhanced Radio Network Temporary Identifier.

51 . A method as set forth in any of claims 41 to 50, wherein said temporary identifier is transmitted to said user equipment from a controller of the first area.

52. A method as set forth in any of claims 41 to 51 , comprising receiving said information in a Media Access Control header.

53. A method as set forth in any of claims 41 to 52, wherein said information comprises a flag.

54. A computer program comprising computer executable instructions which when run on one or more processors perform the method of any of claims 1 to 53.

55. An apparatus comprising at least one processor;

and at least one memory including 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:

set first and second temporary identifiers for said apparatus, wherein said first temporary identifier is associated with a first cell, and said second temporary identifier is associated with at least two further cells at least partially overlapping with said first cell.

56. An apparatus comprising

at least one processor;

and at least one memory including computer program code;

set a temporary identifier for identifying said apparatus when located in a first area; and

when said apparatus moves to a second area at least partially overlapping with said first area, provide information regarding the status of said identifier.

57. An apparatus comprising

at least one processor;

and at least one memory including computer program code;

transmit first and second temporary identifiers to a user equipment, wherein said first temporary identifier is associated with a first cell, and said second temporary identifier is associated with at least two further cells at least partially overlapping with said first cell.

58. An apparatus comprising

at least one processor;

and at least one memory including computer program code;

transmit a temporary identifier for identifying a user equipment located in a first area; and when said user equipment moves to a second area at least partially overlapping with said first area, receive information regarding the status of said identifier.