DETAILED DESCRIPTION OF THE DRAWINGS

[0047] In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular architectures, interfaces, techniques, etc. in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well known devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0048] The present invention is described in the non-limiting, example context of a universal mobile telecommunications (UMTS) 10 shown in FIG. 3 . A representative, connection-oriented, external core network, shown as a cloud 12 may be for example the Public Switched Telephone Network (PSTN) and/or the Integrated Services Digital Network (ISDN). A representative, connectionless-oriented external core network shown as a cloud 14 , may be for example the Internet. Both core networks are coupled to corresponding service nodes 16 . The PSTN/ISDN connection-oriented network 12 is connected to a connection-oriented service node shown as a Mobile Switching Center (MSC) node 18 that provides circuit-switched services. The Internet connectionless-oriented network 14 is connected to a General Packet Radio Service (GPRS) node 20 tailored to provide packet-switched type services which is sometimes referred to as the serving GPRS service node (SGSN). Those skilled in the art will appreciate that the functions may be implemented using individual hardware circuits, using software functioning in conjunction with a suitably programmed digital microprocessor or general purpose computer, using an application specific integrated circuit (ASIC), and/or using one or more digital signal processors (DSPs).

[0049] Each of the core network service nodes 18 and 20 connects to a UMTS Terrestrial Radio Access Network (UTRAN) 24 over a radio access network (RAN) interface referred to as the Iu interface. UTRAN 24 includes one or more radio network controllers (RNCs) 26 . For sake of simplicity, the UTRAN 24 of FIG. 3 is shown with only two RNC nodes, particularly RNC 26 ₁ and RNC 26 ₂ . Each RNC 26 is connected to a plurality of base stations (BS) 28 . For example, and again for sake of simplicity, two base station nodes are shown connected to each RNC 26 . In this regard, RNC 26 , serves base station 28 _1-1 and base station 28 _1-2 , while RNC 26 ₂ serves base station 28 _2-1 and base station 28 _2-2 . It will be appreciated that a different number of base stations can be served by each RNC, and that RNCs need not serve the same number of base stations. Moreover, FIG. 1 shows that an RNC can be connected over an Iur interface to one or more other RNCs in the URAN 24 .

[0050] In the illustrated embodiments, for sake of simplicity each base station 28 is shown as serving one cell. Each cell is represented by a circle which surrounds the respective base station. It will be appreciated by those skilled in the art, however, that a base station may serve to communicate across the air interface for more than one cell. For example, two cells may utilize resources situated at the same base station site.

[0051] A user equipment unit (UE), such as user equipment unit (UE) 30 shown in FIG. 3 , communicates with one or more cells or one or more base stations (BS) 28 over a radio or air interface 32 . Each of the radio interface 32 , the Iu interface, the Iub interface, and the Iur interface are shown by dash-dotted lines in FIG. 3 .

[0052] Preferably, radio access is based upon wideband, Code Division Multiple Access (WCDMA) with individual radio channels allocated using CDMA spreading codes. Of course, other access methods may be employed. WCDMA provides wide bandwidth for multimedia services and other high transmission rate demands as well as robust features like diversity handoff and RAKE receivers to ensure high quality. Each user mobile station or equipment unit (UE) 30 is assigned its own scrambling code in order for a base station 28 to identify transmissions from that particular user equipment unit (UE) as well as for the user equipment unit (UE) to identify transmissions from the base station intended for that user equipment unit (UE) from all of the other transmissions and noise present in the same area.

[0053] Different types of control channels may exist between one of the base stations 28 and user equipment units (UEs) 30 . For example, in the forward or downlink direction, there are several types of broadcast channels including a general broadcast channel (BCH), a paging channel (PCH), a common pilot channel (CPICH), and a forward access channel (FACH) for providing various other types of control messages to user equipment units (UEs). In the reverse or uplink direction, a random access channel (RACH) is employed by user equipment units (UEs) whenever access is desired to perform location registration, call origination, page response, and other types of access operations. The random access channel (RACH) is also used for carrying certain user data, e.g., best effort packet data for, e.g., web browser applications. Traffic channels (TCH) may be allocated to carry substantive call communications with a user equipment unit (UE).

[0054] The present invention, which can be implemented in the example context of the telecommunications system of FIG. 3 , particularly concerns a new and improved technique for establishing a link or leg of a radio connection in the radio access network. The inventive technique is advantageous in the event that a SRNC relocation procedure is performed for the user equipment unit (UE) which has been participating in that link or leg of the radio connection.

[0055] Particularly, in the present invention an end-to-end signaling protocol is utilized to establish, in a radio access network of a telecommunications system, plural distinct connection segments comprising a radio link or leg of a radio connection involving a user equipment unit. An example of an end-to-end signaling protocol is Q.AAL2.

[0056] As used herein, an end-to-end protocol is a protocol which confirms connection setup to an originating node only after a full path to a terminating node is through-connected, so that the user plane is set up and user data can be exchanged between end devices at the originating node and terminating node. Setting up a connection with such an end-to-end protocol typically begins with a message such as an “establish request” message which includes chosen parameters (e.g., CID, VP/VC value, and other traffic parameters in AAL2). The establish request message is sent from an originating node to a terminating node. The terminating node returns an “establish confirm” or similar signaling message. The user plane is then set up between the terminating node and the originating node so that user data can be exchanged between devices at those nodes.

[0057] In the present invention, the plural distinct connection segments extend in series between a device in a first radio network control node and a device in a base station controlled by a second radio network control node. The first radio network control node serves as a serving radio network control (SRNC) node and the second radio network control serves as a drift radio network control (DRNC) node for the radio connection with the user equipment unit. Moreover, in the present invention the confirm establish messages provided by the end-to-end protocol for various distinct connection segments are sequenced so that the originating node does not receive an establish connection confirmation message in the connection layer until the user plane path is fully set up.

[0058] Provision of the plural distinct connection segments is advantageous when performing a SRNC relocation procedure to make the second radio network control node serve as the SRNC for the radio connection involving the user equipment unit. For example, after performance of the SRNC relocation procedure, a retained one of the plural distinct connection segments can still be utilized, e.g., a segment extending between the device in the base station controlled by the second radio network control node and a device at the second radio network control node. The retained one of the connection segments can either be utilized in series with a post-relocation connection segment to establish a path between the device in the base station controlled by the second radio network control node and a diversity handover unit at the second radio network control node, or have its endpoint moved to the diversity handover unit at the second radio network control node.

[0059] Two example modes of implementing the radio connection establishment technique of the present invention are illustrated. A first mode, known also as the three connection segment mode, is illustrated in FIG. 4A . Subsequent events involved with a SRNC relocation procedure facilitated by the first mode are illustrated in FIG. 4 B and FIG. 4C . A second mode, known also as the two connection segment mode, is illustrated in FIG. 5A . Subsequent events involved with a SRNC relocation procedure facilitated by the second mode are illustrated in FIG. 5 B, FIG. 5 C, and FIG. 5D . Other modes of the invention, including modes having greater than three connection segments are within the scope of the present invention.

[0060] Both the first mode and the second mode are hereinafter described with reference to a user equipment unit (UE) 30 for which a radio link or leg of a radio connection is to be controlled initially by serving radio network controller (RNC) 26 ₁ and set up or established via base station 28 _2-1 . The base station 28 _2-1 is controlled by radio network controller (RNC) 26 ₂ , which initially (e.g., before SRNC relocation) functions as a drift radio network controller (DRNC).

[0061] In the three connection segment mode illustrated generally in FIG. 4 A, three distinct connection segments 400 ₁ , 400 ₂ , and 400 ₃ are established between serving radio network controller (RNC) 26 ₁ and a device in base station 28 _2-1 . A first of the connection segments, labeled as segment 400 ₁ in FIG. 4 A, is established between a first device 25 _2-1 at the second radio network control node (drift radio network controller (DRNC) 26 ₂ ) and a device in base station 28 _2-1 . Another (second) of the plural distinct connection segments, labeled as segment 400 ₂ in FIG. 4 A, is established between the first device 25 _2-1 at the second radio network control node and a second device 25 ₂ at the second radio network control node. Yet another (third) of the plural distinct connection segments, labeled as segment 400 ₃ in FIG. 4 A, is established between the second device 25 ₂ at the second radio network control node and a device 27 ₁ at the first radio network control node (serving radio network controller (RNC) 26 ₁ ).

[0062] In the three connection segment mode (as well as in the two connection segment mode hereinafter described), each one of the plural distinct connection segments are segments of a radio link. All but a node internal radio link segment (e.g., all but the second radio link segment in the three connection segment mode) are established using an end-to-end protocol, such as AAL2 signaling, for example. In other words, the end-to-end protocol (e.g., AAL2 signaling) is used to establish node-transcending radio link segments, e.g., radio link segments which do not have both connection points in a same node.

[0063] As explained hereinafter, in the present invention the confirm establish messages provided by the end-to-end protocol for various distinct connection segments are sequenced so that the originating node (the first radio network control node, i.e., serving radio network controller (RNC) 26 ₁ ) does not receive an establish connection confirmation message in the connection layer (via the end-to-end signaling) until the user plane path is fully set up so that user data can be sent between the originating node and the terminating node (e.g., the device in base station 28 _2-1 ).

[0064] To be specific, in the illustration of FIG. 4A the third segment 400 ₂ between ET device 25 ₂ in drift radio network controller (DRNC) 26 ₂ and device 27 ₁ in serving radio network controller (RNC) 26 ₁ is established or set up with AAL2 signaling; the second segment 400 ₂ between ET device 25 _2-1 and ET device 25 ₂ is established or set up using switching in drift radio network controller (DRNC) 26 ₂ ; and the first segment 400 ₁ between a device in base station 28 _2-1 and ET device 25 _2-1 is established or set up with AAL2 signaling. But the originating node (serving radio network controller (SRNC) 26 ₁ ) does not receive an establish confirmation signaling message until the entire user plane path has been setup between the originating node and the terminating node (e.g., the device in base station 28 _2-1 ). This means that any other establish confirmation signaling sent with respect to any other connection segment (e.g., connection segment 400 ₁ ) must be properly coordinated or sequenced. In particularly, establish confirmation signaling must be sent beginning in closest order of proximity of the corresponding connection segment to the terminating node.

[0065] The present invention thus differs from prior practice in various ways. For example, in prior practice usage of an end-to-end signaling protocol would mean set up or establishment of a radio link between end points of the device 27 ₁ and a device in base station 28 _2-1 .

[0066] In the illustrated embodiment, the first device 25 _2-1 and the second device 25 ₂ at the second radio network control node 26 ₂ respectively can be or include a first connection point and a second connection point (e.g., at/in a first extension terminal [ET] and a second extension terminal [ET], respectively). In such implementation, the ET device 25 ₂ serves to interface drift radio network controller (DRNC) 26 ₂ over inter-RNC link 29 to serving radio network controller (RNC) 26 ₁ . ET device 25 _2-1 and ET device 25 _2-2 serve to interface or connect drift radio network controller (DRNC) 26 ₂ to base station 28 _2-1 and base station 28 _2-2 , respectively.

[0067] Thus, in the illustrated embodiment, connection points are situated at the first device 25 _2-1 and the second device 25 ₂ at the second radio network control node 26 ₂ . The term “connection point” is utilized since at these devices the end-to-end signaling protocol sets up a connection segment endpoint for each connection segment. In the illustrated embodiment wherein Q.AAL2 is employed to setup AAL2 channels, AAL2 channels are multiplexed onto ATM virtual channels (VCs) [multiplexing being utilized for different layers]. Therefore, while “connection point” is the more generic descriptor for such points, in the more specific illustrated case of AAL2 such points are also herein referred to as “multiplexing points”.

[0068] As mentioned above, in the illustrated embodiment extension terminals (ETs) serve as specific examples of first device 25 _2-1 and the second device 25 ₂ . Various aspects of extension terminals (sometimes referred to as “exchange terminals”) are generally described, e.g., in one or more of the following (all of which are incorporated herein by reference: U.S. Pat. No. 6,128,295; U.S. patent application Ser. No. 09/249,785, entitled “ESTABLISHING INTERNAL CONTROL PATHS IN ATM NODE”, filed Feb. 16, 1999; U.S. Pat. Nos. 6,128,295; 6,088,359; 5,963,553; 6,154,459; and 6,034,958.

[0069] The drift radio network controller (DRNC) 26 ₂ comprises a diversity handover unit (DHO) 27 ₂ shown in FIG. 3 , as well as other units and boards not illustrated. Among the other units of drift radio network controller (DRNC) 26 ₂ not illustrated in FIG. 3 can be a switch (e.g., a cell or packet switch) for interconnecting the constituent elements of drift radio network controller (DRNC) 26 ₂ . Although such a switch is not shown in FIG. 3 , an example radio network controller having such a switch is shown in FIG. 10 .

[0070] In the illustrated embodiment, the device 27 ₁ is a diversity handover unit (DHO). The device 27 ₁ is in serving radio network controller (RNC) 26 ₁ , which is involved in the third connection segment 400 ₃ of FIG. 4A . The serving radio network controller (RNC) 26 ₁ also has extension terminals in like manner as drift radio network controller (DRNC) 26 ₂ already-described, including extension terminal ET 25 ₁ which serves to interface serving radio network controller (RNC) 26 ₁ over inter-RNC link 29 to drift radio network controller (DRNC) 26 ₂ . Although not shown in FIG. 4 A, the person skilled in the art will appreciate that extension terminals (ETs) can also be employed for connection to each of the base stations controlled by serving radio network controller (RNC) 26 ₁ . Furthermore, the serving radio network controller (RNC) 26 ₁ can also have a switch for interconnecting its constituent elements.

[0071] As mentioned above, the modes of the present invention are particularly advantageous for facilitating subsequent performance of a SRNC relocation or moveover procedure. It will be recalled from the previous discussion that an SRNC relocation procedure occurs when it is determined that the role of a serving radio network controller (SRNC) for a radio connection involving a user equipment unit (UE) should be moved from one radio network controller to a node which, prior to the SRNC relocation, had been serving as a drift radio network controller (DRNC).

[0072] FIG. 4 B and FIG. 4C illustrate certain basic actions pertaining to a SRNC relocation performed after a radio link has been set up in accordance with the three connection segment mode of FIG. 4A . Advantageously the first connection segment 400 ₁ can be retained after completion of the SRNC relocation to comprise the radio connection with user equipment unit (UE) 30 . The first connection segment 400 ₁ is the connection segment between base station 28 _2-1 and ET device 25 _2-1 . FIG. 4B shows that, upon implementing SRNC relocation, the first connection segment 400 ₁ can still be utilized, along with two new additional connection segments, e.g., connection segment 400 ₄ and connection segment 400 ₅ . The new connection segment 400 ₄ is established or set up between ET device 25 _2-1 of serving radio network controller (RNC) 26 ₁ and the diversity handover unit (DHO) 27 ₂ of drift radio network controller (DRNC) 26 ₂ . The new connection segment 400 ₅ is established or set up between the diversity handover unit (DHO) 27 ₂ of drift radio network controller (DRNC) 26 ₂ and the core network 16 . Both the new connection segment 400 ₄ and new connection segment 400 ₅ , like connection segment 400 ₁ before them, are preferably set up using an end-to-end signaling protocol such as AAL2.

[0073] FIG. 4B also shows by broken lines that the former second connection segment 400 ₂ and former third connection segment 400 ₃ are no longer needed after the SRNC relocation. FIG. 4C shows that, after SRNC relocation, the former second connection segment 400 ₂ and former third connection segment 400 ₃ have been broken down, leaving only the retained connection segment 400 ₁ , new connection segment 400 ₄ , and new connection segment 400 ₅ .

[0074] Thus, subsequent to performance of the SRNC relocation procedure, the first connection segment 400 ₁ is utilized in series with two post-relocation connection segments, e.g., new connection segment 400 ₄ and new connection segment 400 ₅ , to establish a path (e.g., radio link or leg) between a device in the base station controlled by the second radio network control node (e.g., base station 28 _2-1 ) and the core network 16 .

[0075] In the two connection segment mode illustrated generally in FIG. 5 A, two distinct connection segments 500 ₁ and 500 ₂ are established between serving radio network controller (RNC) 26 ₁ and base station 28 _2-1 . A first of the connection segments, labeled as segment 500 ₁ in FIG. 5 A, is established between a device (e.g., device 25 ₂ ) at the second radio network control node (drift radio network controller (DRNC) 26 ₂ ) and a device in base station 28 _2-1 . Another (second) of the plural distinct connection segments, labeled as segment 500 ₂ in FIG. 5 A, is established between the device (e.g., device 25 ₂ ) at the second radio network control node and a device (e.g., device 27 ₁ ) at the first radio network control node. Thus, in contrast to the three connection segment mode, in the two connection segment mode the first segment, e.g., the segment 500 ₁ having a first end point connected to base station 28 _2-1 has its second endpoint connected to ET device 25 ₂ rather than to ET device 25 _2-1 .

[0076] In the two connection segment mode, each one of the plural distinct connection segments are segments of a radio link. As in the three connection segment mode, each such radio link segment is established using an end-to-end protocol, such as AAL2 signaling, for example. To be specific, the second segment 500 ₂ between ET device 25 ₂ and DHO 27 ₁ is established or set up with AAL2 signaling; and the first segment 500 ₁ between the device in base station 28 _2-1 and ET device 25 ₂ is established or set up with AAL2 signaling. In like manner as the three connection segment mode, establish confirmation signaling must be sent beginning in closest order of proximity of the corresponding connection segment to the terminating node (e.g., base station 28 _2-1 ), sot that the originating node (e.g., serving radio network controller (SRNC) 26 ₁ at which DHO 27 ₁ is situated) receives establish confirmation signaling only after the entire user plane path has been setup. It is again mentioned that this differs from prior practice, since in prior practice usage of an end-to-end signaling protocol would mean set up or establishment of a radio link between end points of the device 27 ₁ and a device in base station 28 _2-1 .

[0077] In the two connection segment mode, a first connection segment 500 ₁ is referred to as a first or retainable one of the plural distinct connection segments. The device in drift radio network controller (DRNC) 26 ₂ which forms a second endpoint of the first connection segment 500 ₁ is, in the illustrated example embodiment, a connection point (e.g., multiplexing point at an extension terminal [ET]) situated between an unillustrated switch of the second radio network control node 26 ₂ and the inter-RNC link 29 to the first radio network control node 26 ₁ . Although the switch comprising the example, representative drift radio network controller (DRNC) 26 ₂ is unillustrated in FIG. 5 A, its nature and operation will be understood from the example node shown in and subsequently described with reference to FIG. 10 .

[0078] FIG. 5 B, FIG. 5 C, and FIG. 5D illustrate certain basic actions pertaining to a SRNC relocation performed after a radio link has been set up in accordance with the two connection segment mode of FIG. 5A . FIG. 5B shows that the SRNC relocation will involve a new connection segment 500 ₃ which extends between core network 16 and the DHO device 27 ₂ of drift radio network controller (DRNC) 26 ₂ . The new connection segment 500 ₃ , like connection segment 500 ₁ before it, is preferably set up using an end-to-end signaling protocol such as AAL2.

[0079] Further, as shown by arrow S in FIG. 5C, a second endpoint of connection segment 500 ₁ is moved from ET device 25 ₂ to the DHO device 27 ₂ . The first connection segment 500 ₁ is the connection segment which has its first endpoint connected to base station 28 _2-1 . With its second endpoint thusly moved, the first connection segment 500 ₁ can be retained after completion of the SRNC relocation to comprise the radio connection with user equipment unit (UE) 30 .

[0080] FIG. 5C also shows by broken lines that the former second connection segment 500 ₂ is no longer needed after the SRNC relocation. FIG. 5D shows that, after SRNC relocation, the former second connection segment 500 ₂ has been broken down, leaving only the retained connection segment 500 ₁ and new connection segment 500 ₃ .

[0081] Thus, subsequent to performance of the SRNC relocation procedure, the first connection segment 500 ₁ , with its second endpoint moved within drift radio network controller (DRNC) 26 ₂ , is utilized in series with post-relocation connection segment 400 ₃ , to establish a path (e.g., radio link or leg) between the base station controlled by the second radio network control node (e.g., base station 28 _2-1 ) and the core network 16 .

[0082] FIG. 10 illustrates, in somewhat more detail, an example non-limiting RNC node 26 _G of the present invention. RNC node 26 _G of FIG. 10 can represent an serving RNC (SRNC) or a drift RNC (DRNC). It so happens that the RNC node 26 of FIG. 10 is a switched-based node having a switch 120 . The switch 120 serves to interconnect other constituent elements of RNC node 26 _G . Such other constituent elements include extension terminals [ETs] 125 _G-1 through 125 _G-n , extension terminal 125 ₁ which connects RNC node 26 _G via the inter-RNC link 29 to another radio network controller; and extension terminal 124 . Extension terminals 125 _G-1 through 125 _G-n essentially function to connect RNC node 26 _G to the base stations 28 served by RNC node 26 _G ; extension terminal 124 connects RNC node 26 across the Iu interface to the core network 16 . Yet other constituent elements of RNC node 26 _G include diversity handover unit 27 _G ; codex 130 ; timing unit 132 ; a data services application unit 134 ; and, a main processor 140 .

[0083] FIG. 11 illustrates, in non-limiting manner, more details of an example base station (BS) node 28 in accordance with one embodiment of the present invention. As with RNC node 26 , the base station (BS) node 28 of FIG. 11 is a switched-based node having a switch 220 which serves to interconnect other constituent elements of base station (BS) node 28 . Such other constituent elements include extension terminal (ET) 222 ; BS main processor 240 , and interface (IF) boards 242 . It is an interface board 242 which, in the scenario of FIG. 4 A and FIG. 5 A, is the device in the base station 28 _2-1 which serves as the first endpoint of the first connection segment. This interface board 242 is sometimes referred to as the RX/TX device.

[0084] Extension terminal (ET) 222 connects base station (BS) node 28 to radio network controller (RNC) node 26 , and thus comprises the Iub interface. Preferably included in the extension terminal 222 is a function which provides, e.g., multiplexing and demultiplexing and (optionally) queuing with regard to differing protocols of cells. Alternatively, a separate unit which performs these functions can be situated in BS 28 _2-1 external to extension terminal ET.

[0085] The embodiment of base station (BS) node 28 illustrated in FIG. 11 is housed in a rack having multiple subracks. Each subrack has one or more boards, e.g., circuit boards, mounted thereon. A first subrack 250 contains boards for each of extension terminal 222 ; BS main processor 240 , and interface boards 242 . Each of the interface boards 242 is connected to a board on another subrack, e.g., one of the transmitter boards 260 or one of the receiver boards 270 . Each receiver board 270 is connected to share certain transmitter/receiver resources in a corresponding transmitter board 260 , with the transmitter board 260 being connected to a corresponding one of amplifiers and filters board 280 . The amplifiers and filters board 280 is connected to an appropriate antenna 39 . For example, interface board 242 _1-T is connected to transmitter board 260 ₁ , while interface board 242 _1-R is connected to receiver board 270 ₁ . The pair of transmitter board 260 ₁ and receiver board 270 ₁ is, in turn, connected to amplifiers and filters board 280 ₁ . Similar connections exist for a second pairing of transmitter board 260 ₂ and receiver board 270 ₂ , which interface via interface board 242 _2-T and interface board 242 _2-R , respectively. Each transceiver 38 of FIG. 2 thus comprises a subrack which includes a transmitter board 260 , a receiver board 270 , and amplifiers and filters board 280 .

[0086] In one example, non-limiting embodiment, base station (BS) node 28 is an ATM-based node, with interface boards 242 performing various ATM interfacing functions. The transmitter boards 260 and receiver boards 270 each include several devices. For example, each transmitter board 260 includes unillustrated elements such as an interface connected to its corresponding interface board 242 ; an encoder; a modulator; and, a baseband transmitter. In addition, the transmitter board 260 includes the transmitter/receiver resources which it shares with receiver board 270 . Each receiver board 270 includes unillustrated elements such as an interface connected to its corresponding interface board 242 ; a decoder; a demodulator; and, a baseband receiver. Each amplifiers and filters board 280 includes amplifiers, such as MCPA and LNA amplifiers.

[0087] The distinct plural radio connection or link segments of the present invention can be established using binding information to bind together a call layer and a connection layer. In this regard, telecommunications networks are typically conceptualized as having layered functionalities. The physical layer comprises a network of switches and cables (e.g., trunk lines) which are employed to connect devices (e.g., telephones, either mobile or stationary) involved in a call (e.g., a “connection”). The connection layer is an abstraction that comprises a model of the physical network. Connection handling (which is performed over the connection layer) relates to the set up and release of connections and to the control of the physical telecommunications network. The call layer is involved in service handling, which includes service control, service execution, service signaling, service installation, service modification, and service administration. Within each layer information is transferred over signaling entities within the layer.

[0088] In some telecommunication systems, the call layer information and the connection layer information is signaled and routed along the same path from a call origin to a call destination. In such case, the resources needed for the call establishment are reserved hop by hop (e.g., as the information is signaled and routed from switch to switch through the physical network). As the call layer and connection layer are therefore closely coupled to each other, the binding between the call layer and the connection layer is resolved in runtime.

[0089] Modem telecommunication networks usually have the call layer and the connection layer separated from one another. As a consequence of the separation of the call layer and the connection layer, different networks are used for the call establishment and the connection establishment. The two networks (the call layer network and the connection layer network) usually have different topologies.

[0090] In operation, in setting up a call usually a call layer connection is initially established over the call layer network between two devices. Typically establishing the call layer connection involves exchange of control information that does not need any user plane (e.g., physical layer) connection. Subsequently, when a user plane connection is needed over the physical layer, a connection is established in the connection layer.

[0091] The two connections—the call layer connection and the connection layer connection—are routed from the same origin to the same destination. However, in view of the differing topologies of the call layer network and the connection layer network, the two connections do not have to be routed along the same path. The advantage of separate routing of the call layer connection and the connection layer connection is that resources for the user plane connection are only reserved and used when needed. Examples of call and connection separated telecommunications networks are provided in the following, all of which are incorporated herein by reference in their entirety: Swedish Patent Application 9601605- 0 , filed Apr. 26, 1996; U.S. Pat. Nos. 5,809,129; and, 5,710,882.

[0092] The separation of the call layer and the connection layer does, however, require some type of mechanism to bind the two layers to each other at certain nodes where the two layers meet. The signaling protocol of each layer needs to carry the binding mechanism, e.g., binding information. Typically, existing networks with existing protocols are used, and the binding information must be fit into already defined information entities within those protocols.

[0093] In the above regard, both in a core network and in a radio access network, the call layer generally uses a signaling system No. 7 (SS7) network or a TCP/IP network for call control signaling. On top of the SS7 or the TCP/IP protocol stacks there is an application protocol, such as RNSAP or RANAP. The RNSAP and RANAP protocols are used end-to-end in the network. Application specific resources, such as diversity handover units (DHOs) and codecs (coders/decoders) are handled and reserved at the call layer.

[0094] In one of its aspects, the present invention provides various binding information techniques for the multiple connection segment modes when the call and the connection layers are separated in a telecommunications network. An example binding technique for the three connection segment mode (of FIG. 4 A- FIG. 4C ) is illustrated in FIG. 6 . FIG. 6 shows, from a layering perspective, the three nodes of the serving radio network controller (SRNC) 26 ₁ , the drift radio network controller (DRNC) 26 ₂ , and the base station 28 _2-1 . In FIG. 6, a physical layer is illustrated as being below dashed double-dotted line 630 . The physical layer comprises a network of switches and cables or links (e.g., trunk lines) which are employed to connect devices such as diversity handover unit (DHO) 27 ₁ and device 624 ₃ . In the illustrated embodiment, each of the three nodes has a switch, e.g., switch 120 ₁ for serving radio network controller (SRNC) 26 ₁ ; switch 120 ₂ for drift radio network controller (DRNC) 26 ₂ ; and switch 120 ₃ for base station 28 _2-1 . To a switch port of switch 120 ₁ which are outgoing from end node 26 ₁ is connected extension terminal 25 ₁ , only one such extension terminal 25 ₁ being shown in FIG. 6 for sake of simplification. Likewise, respective switch ports of switch 120 ₂ of drift radio network controller (DRNC) 26 ₂ are connected to extension terminals 25 ₂ and 25 _2-1 , which have been discussed above. A switch port of switch 27 ₃ of base station 28 _2-1 is connected to extension terminal 25 ₃ . As is understood to those skilled in the art, it is through extension terminals such as extension terminals 25 in FIG. 6 that a switch is connected in the physical layer to other nodes.

[0095] The information used to identify a connection endpoint, known herein as connection endpoint information, varies from switch to switch, and depends on conventions of the switch vendor/manufacturer. The connection endpoint information can thus be vendor specific for a physical layer entity, and may take the form of a concatenation of one or more of a node identifier, a hardware cabinet rack, a hardware slot, a hardware port, and a resource, for example.

[0096] The connection layer is shown in FIG. 6 above the physical layer, e.g., between dashed double-dotted line 630 and dash dotted line 640 . In each node, the connection layer includes a connection layer control process. For example, a connection layer control process 42 ₁ is performed at serving radio network controller (SRNC) 26 ₁ , a connection layer control process 42 ₂ is performed at drift radio network controller (DRNC) 26 ₂ ; and a connection layer control process 42 ₃ is performed at base station 28 _2-1 . The call layer is shown in FIG. 6 above the connection layer, e.g., above dash dotted line 640 . In each node, the call layer includes a connection layer control process. Again by way of example, a call layer control process 52 ₁ is illustrated in FIG. 6 for serving radio network controller (SRNC) 26 ₁ ; a call layer control process 52 ₂ is illustrated for drift radio network controller (DRNC) 26 ₂ ; and a call layer control process 52 ₃ is illustrated for base station 28 _2-1 .

[0097] In general, whenever a user plane connection is needed to be set up in the physical layer, an order is given in the form of a connection request from the call layer to the connection layer. The connection endpoints of the application specific resources must be addressable at the connection layer. The connection is established using an appropriate connection layer signaling protocol, e.g., B-ISUP signaling for ATM connections or Q.AAL2 for AAL2 connections. The connection layer signaling is routed through the connection layer and controls reservation and through connection of connection layer resources (e.g., switches and extension terminals) along the path to the destination end node.

[0098] An example of using binding information for the three connection segment mode of the present invention is described with reference to certain example basic actions in FIG. 6 . In FIG. 6 and similar figures, the term “connection point” encompasses endpoints of the connection segments described above. Moreover, when the connection segment endpoint is also an endpoint of the overall connection, the further refined term “connection endpoint” may be employed for more specificity.

[0099] Concerning first the third segment 400 ₃ (see FIG. 4A ), as action 6-1 the call layer (more specifically call layer control process 52 ₂ at drift radio network controller (DRNC) 26 ₂ ) obtains a binding reference to represent a connection point associated with the connection point (e.g., multiplexing point) furnished by extension terminal 25 ₂ . Since the connection points are selected by the connection layer, when setting up the connection a table, such as table 70 maintained by connection layer process 70 ₂ , cannot reserve a connection point in advance. Therefore, in accordance with one aspect of the present invention, the value of the binding reference obtained as action 6-1 can be in a predetermined range which is reserved for setting up network-wide AAL2 connections to a connection/multiplexing point (e.g., a predetermined range binding reference values which specifies that the connection is to be routed to an incoming connection/multiplexing point, and therefore is a connection point corresponding to an endpoint of a segment). The terminating node can then, by examining the binding reference, determine from the range to which the binding reference belongs that it is for setup of a connection segment. The binding reference can be obtained from the connection layer, or alternatively obtained from the call layer. FIG. 6 particularly shows as action 6-1 obtaining the binding reference. The binding reference can be obtained, but does not have to be obtained, from a table such as table 70 ₂ . Table 70 ₂ associates the binding reference with the appropriate connection point, e.g., connection point 636 ₂ at extension terminal 25 ₂ in FIG. 6 . The connection point is described by connection point information which, as mentioned above, can be vendor specific information.

[0100] As an example, the binding information can be standardized for Q.AAL2. In particular, such binding information is standardized in ITU-T Q.2630.1 to be a fixed size field of four octets. The binding information is named “Served User Generated Reference” (SUGR) in the Q.2630.1 specification. However, the ITU-T Q.2630.1 standard does not limit or imply anything regarding how those values are assigned to the SUGR.

[0101] Another possibility for obtaining the connection point is to have table 70 ₂ associate a binding reference (e.g., any appropriate SUGR value) and a predetermined value, e.g., a predetermined or null value employed specifically for this purpose, instead of a connection point value. Upon finding the predetermined (e.g., null) value associated with a binding reference in table 70 ₂ , the connection layer knows it is a segment setup and that the connection is only to be routed to the connection point. In this situation any SUGR value can be used and no SUGR range has to be reserved. Alternatively, these two techniques can be used in conjunction with one another—both a predefined range and also the predetermined or null value can be employed as a precaution.

[0102] As action 6-2, the call layer control process 52 ₂ of drift radio network controller (DRNC) 26 ₂ transmits a call layer signaling message to serving radio network controller (SRNC) 26 ₁ . The call layer signaling message of action 6-2 can include the binding information (BI) and an ATM end system address (AESA) of drift radio network controller (DRNC) 26 ₂ in FIG. 6 . The call layer signaling message of action 6-2 can be in the form of an appropriate existing protocol, such as RANAP, RNSAP, and NBAP when the telecommunications network is a radio access network known as UTRAN. In any call and connection separated network the call layer must extend this information in order to make it possible for the connection layer to route the connection. As is understood generally and illustrated subsequently, the AESA of drift radio network controller (DRNC) 26 ₂ carried in the call layer signaling message is used for signal routing to drift radio network controller (DRNC) 26