FI119713B - The switching device - Google Patents

Description

FIELD OF THE INVENTION

The present invention relates to telecommunication and in particular to a device for switching in a telecommunication system.

BACKGROUND OF THE INVENTION

A central component of communication systems are the switching elements that control substantially all communication processes in the network. Many traditional switching elements are based on time division multiplexing (TDM) and are based on vendor-specific platforms. Advanced 10 Telecom Computing Architecture (ATCA) is an evolving open standard optimized for next-generation telecommunications equipment. Standardization work has brought together several telecommunications equipment manufacturers to work together and develop modular and interoperable hardware and software on a common platform 15 Typically, new designs have already targeted packet networks, so that traditional TDM signals and protocols have not received much attention at the design stage. The basic assumption seems to be that the switching will be based on open server technologies and IP based networking, and TDM interface modules will be arranged to convert between TDM and 20 packet protocols. In many systems, this means replacing traditional TDM switching matrices with an Ethernet switching field.

However, the installed hardware base is massive and adopting new architectures will be a challenging task. As a result, one of the key drivers that has emerged in the design of new systems recently has been the ease of transition from existing TDM systems to the new packet-based architecture. However, the major requirement is that new IP networks must be able to work with existing TDM networks. This means that the switching mechanisms must support the simultaneous use of TDM and IP communication resources for at least some time. Other factors such as the ability to reduce development costs by re-using, as far as possible, well-established algorithms and practices in existing technologies are also relevant in this regard.

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SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a switching device or relevant elements to a switching apparatus in such a way that the disadvantages of TPM-based switching to packet switched switching are reduced.

The objects of the invention are achieved by a method, a device, a control unit, an interface unit, a computer program product and a computer program distribution medium characterized by what is stated in the independent claims. Preferred embodiments of the invention are described in the dependent claims.

The invention is based on the idea of using logical identities such that the control of call control functions and routing information related to the terminals can be performed separately and thus the dependence of the call control functions on the properties of the transmission network is reduced. The information is combined at such a point in the switching procedures that the existing signaling procedures can be optimally utilized.

An advantage of the solution according to the invention is that it facilitates the technical and economic investment that follows the transition from time-division switching to packet-based switching systems.

BRIEF DESCRIPTION OF THE PI

The invention will now be described in more detail by means of preferred embodiments with reference to the accompanying drawings, in which:

Figure 1 provides a simplified representation of the main elements of the TETRA radio system 10 used as an embodiment;

Figure 2 shows the reference hardware structure of the device used as an embodiment;

Figure 3A shows an exemplary structure of elements in a functional situation related to an embodiment;

Fig. 3B shows a signaling diagram corresponding to Fig. 3A;

Figure 4A shows another exemplary elementary structure of pre-30 elements in a handover situation;

Fig. 4B shows a signaling diagram corresponding to Fig. 4A;

Fig. 5A shows another exemplary element structure in an operational situation in which one user 35 is in a public telephone network; | 3

Fig. 5B shows a signaling diagram corresponding to Fig. 5A;

Fig. 6A shows another exemplary element structure in the event of a failure;

Fig. 6B shows a signaling diagram corresponding to Fig. 6A; Figure 7 shows a reference structure of a base station; and

Figure 8 shows a signaling diagram illustrating an exemplary procedure for call setup and speech unit operations at a base station.

DETAILED DESCRIPTION OF THE INVENTION

It should be noted that the following embodiments are exemplary. In addition, while the disclosure may refer to a "particular" embodiment or "some" embodiments at various points, the reference may not necessarily refer to the same embodiment, or the characteristic in question is not related to a particular embodiment. The individual features 15 of the various embodiments may be combined to provide additional embodiments.

The invention will now be described using TETRA air interface terms and elements as defined in the European Telecommunication Standards ETSI EN 300 392 series, without limiting the invention to this one radio network technology. The present invention can be applied to any communication technology in which the data traffic streams of a plurality of access units are processed by a shared switching and control function.

Figure 1 provides a simplified representation of the TETRA radio system 10 used as an embodiment. The radio system 100 comprises a switching and control general structure (SwMI) 102 and a mobile station (MS) 104. The SwMI 102 is a device for such voice and data (V + D) network. , which allows the user terminals to communicate with each other. In Figure 1, the SwMI comprises a single digital exchange (DXT) 104 and a base station (TBS) 108, but in real implementations, the number of elements and their interconnections may vary greatly according to the implementation.

A wide terminal of devices from mobile station (MS) 104 is configured to use SwMI via a glue interface 110. Another type of subscriber terminal, access point 112, communicates with SwMI 102 through access point 114, where the connection is provided using, for example, E1, ISDN, BA or IP protocols. In practice, the radio system may comprise multiple access points 35112 and corresponding different types of interfaces 114. In addition, SwMI comprises an interface 4116 for interfacing with other networks, such as public telephone (PSTN), GSM, WCDMA, conventional analog, LAN, WAN and the like. The protocols associated with the various interfaces are implementation-specific arrangements and are known in the art.

2 is a block diagram showing a reference hardware structure of a device suitable for the switching and control functions according to the invention. The reference apparatus will be described in connection with the digital TETRA exchange shown in Figure 1. The device includes one or more access units 20, 21, 22, 23, 24, a control unit 25, a switching matrix 26 and possibly one or more complete network access point 10 units 27. The units of the device may be implemented as microcomputer devices and systematically interconnected via switching field 26. based on received and / or stored information according to predetermined, substantially programmed processes.

In the following, the roles of the elements and their functions will be described in more detail with the aid of some exemplary embodiments and communication situations.

The interface unit 20, 21,22, 23, 24 represents here a functional unit which provides an entry / exit point through which data streams can be controlled to and from the device. Outwardly, the interface unit provides a plurality of external communication resources 20 that can be utilized by the interface unit as discrete message paths. The blocks of data to be transferred to and from external sources are transported using these external communication resources. Inwardly, the interface unit provides an internal communication resource through which the interface unit may exchange information blocks with the switching field 26. The transmission-25 technique used to connect to external sources may vary, but typically one interface unit is implemented with one technique. The type of communication resource varies according to the transmission technology and protocols used. For example, with reference to Figure 1, in conventional TET-RA systems, the connection between digital exchanges and base stations is implemented by 2Mbit / s standards in accordance with CCITT G.703 and G.704 recommendations. Each TETRA bearer uses a 64 kbit / s time slot from a 2 Mbit / s PCM link. At the air interface, the TETRA TDMA frame comprises four time slots with an average throughput of 8kbit / s. Thus, the time slot of the TETRA air interface corresponds to the PCM sub-slot in transmission and the access unit manages a plurality of sub-slots as separate communication resources.

On the other hand, the device used in the embodiment also has IP transmission! possible. For example, the base station may encapsulate the TETRA speech frame corresponding to the air interface time slot 5 into an IP packet, append the source address to the gateway interface time slot, and send the IP packet to a predetermined destination address of the switching device interface unit. The IP migration endpoint can be implemented, for example, as a 1GB Advanced Mezzaine Card. The TETRA air boundary-5 surface time slot thus corresponds to a specified combination of source and destination addresses for transmission, and the combination unit considers such a combination as a separate communication resource.

It should be noted that the foregoing examples are intended to illustrate the invention, not to limit its scope. It will be appreciated that several other transmission technologies and interface protocols not explicitly mentioned herein are possible, and it will be straightforward for a person skilled in the art to determine the separate communication resources of the applicable technology.

The switching matrix 26 provides hardware and algorithms for combining functional units, transport channels or communication circuits to transmit signals. The switching matrix used as an embodiment is packet-based, which means that the device control unit does not centrally control the mapping between incoming and outgoing communication resources, as in conventional TDM switching matrices. During operation, the switching matrix receives, in one of its input ports, a data packet carrying the header information, and based on the header information, the switch-field matrix defines a destination port and forwards the packet to a specified destination port. It should be noted that the coupling matrix display only shows a basic structure essential to illustrate embodiments of the invention. It will be apparent to one skilled in the art that typical switching device implementations are complex architectures that provide a variety of paths, for example, a different type of saliva for traffic and duplication. For example, the switching matrix may comprise one packet-based part for switching user traffic and one signaling traffic, or the switching matrix may comprise a packet-based part for switching user traffic and control bus signaling for traffic.

The control unit 25 represents a functional unit which monitors the connections and resources to be connected to the device 30 and, on the basis of this tracking, handles the various interconnection functions of the device in the communication system to which the device belongs. The control unit comprises at least mobility management functions for controlling the movement of mobile stations and call control functions for establishing a bearer path from the origin to the end of the network (35). The control unit may be implemented as an integrated part or represent a combined combination separately, separately managed or separately managed. The call control unit and the mobility management unit In an embodiment of the TETRA digital control unit, the control unit can be implemented as a call control microcomputer unit, whose main functions are related to call control processing, radio network re-5 T and O nce T roaming and intercommunication. telecommunication system functions, and typically they are duplicated to provide greater redundancy.

The network interface unit 27 here represents a set of one or more interface units 10, each of which may be dedicated to managing connections to other TETRA networks or other networks in general. Typically, network interface units also include devices and algorithms for decoding TETRA speech coding and encoding speech data when it enters the device from other networks.

It should be noted that Figures 1 and 2 show only the elements necessary to illustrate the present invention. It will be obvious to a person skilled in the art that mobile stations and elements of a switching and control general structure include a number of other elements and functions not explicitly described herein. In addition, the blocks represent logical or functional units that may be implemented within or by one or more physical units, whether represented by one or more of the blocks in Figures 1 and 2.

Figure 3A shows an exemplary structure of the TETRA communication system of Figures 1 and 2 and its digital control panel. FIG. 3 illustrates an operational situation in which each of the three mobile terminals MT1, MT2, MT3 is located under a different base station BS1, BS2, BS3 and communicates with base stations over the air interface AIF. These base stations are connected to the digital exchange over the transmission interface TIF, the end points of which are the digital exchange interface units IFU1, IFU2. The IFU1, iF2 interface units are interconnected by a packet switched Ethernet field SM. BS1 connects to digital exchange 30 via iFU1 and BS2 and BS3 via IFU2. In the first exemplary operating situation of Figure 3A, each of the IFU1 and IFU2 interface units operates using PCM frames.

FIG. 3B shows a signaling diagram illustrating an exemplary mode of operation associated with call set-up and single speech unit transfer in group call MT1, MT2, MT3 of FIG. 3A. It should be noted that although the procedures described herein are related to voice communications, the invention is warranted £ 7 is charged for any type of media connection, such as data and video calls. In addition, the number of terminals in the connection is not limited to any particular number, which means that the invention is applicable to both individual calls and group calls of any size.

Initially, the mobile terminals are registered in the system and the first mobile terminal MT1 transmits (step 3-1) over the air interface a signaling message which carries a call set-up request to the first base station BS1. Signaling messages are identified by the logical channel used to carry the message at the air interface. The base station 10 transmits the call set-up request to the PVM signaling slot and thus forwards (step 3-2) the signaling message to the first access unit IFU1. The interface unit may have a persistent description of signaling messages arriving at a particular PCM time slot, or may be arranged to receive a description of the signaling message reception times. In either case, the description provides a target-15 address that can be used by the access units to reach the control unit to carry a particular type of signaling. The first access unit IFU1 thus encapsulates the call set-up request with the Ethernet frame, assigns it an address to the address, which takes it to the control unit and forwards the packet to the switching field for transport (step 3-3) to the control unit.

Upon receipt of a call set-up request, the control unit according to the invention may perform any conventional procedure for establishing a call by determining the parties involved in the call and allocating physical resources at the air interface and the transmission boundary at the surface. In addition, the control unit provides (step 3-4) imaging information for connecting the call.

To accomplish this, the control unit generates a connection identity, an identity that uniquely identifies a connection at least in a digital exchange for at least the duration of the connection. This connection identity provides a logical reference for information associated with the connection being established and is virtually independent of any physical system elements (base station, access unit, etc.) involved in the establishment of the call.

Further, to provide the imaging information, the control unit determines at the transmission interface a TIF communication resource corresponding to a communication resource that can be allocated to a separately identifiable communication terminal at the outer end. For example, in the present embodiment, such a communication path 35 at the outer end may be a TETRA air interface channel that is allocated to a particular call, and the communication resource at the transport interface corresponds to a PCM-8 sub-slot allocated to the TETRA air interface channel. The control unit now assigns to each communication resource (PCM sub-time slot) a resource identity, a logical identity that uniquely identifies the communication resources available for communications, at least in the digital exchange, Resource-5 identity thus represents a logical description between at least two physical resources. The logical representation may be static such that, for example, a particular gateway interface channel corresponds to a specific PCM time slot, or dynamic such that, for example, a PCM time slot is mapped to a gateway interface channel during connection establishment. In any case, this means that the physical characteristics of the communication resources associated with the resource ID may be completely unaffected by the call control functions that refer to the resource ID.

When the air interface channels are allocated to the mobile terminals MT1, MT2, MT3 at base stations BS1, BS2, BS3, the corresponding resource IDs are simultaneously associated with the connection ID. Similarly, when a change occurs in the air interface allocations, the combination of communication resources associated with the resource ID stored in the control unit is adjusted accordingly.

In addition, the control unit also determines the addresses that your switching matrix will apply to reach the output ports among a plurality of IFU1, IFU2. Any access unit having a communication resource associated with at least one resource identity and connection ID is a relevant access unit. In the case used as an embodiment, the addresses are the {Media Access Control) MAC addresses that are applied to point to the interface units in the switching field.

25 Thus am description information for the call comprises yhteystunnuk the resource identifiers and addresses of the parties to the access unit, as described above. It should be noted that virtually all information needed to determine imaging information may be readily available at the control unit via basic call setup signaling. For example, if the control unit receives information during the Mobility Signaling from the allocated lime interface resources in the form that it is prepared to interpret the change in the air interface as a change in resource identity determination, substantially no additional signaling between the mobile terminals and the network elements in the field is required. implement. On the other hand, if the mobility management signaling messages delivered to the control unit do not directly indicate to the control unit a particular air interface resource, the mobility management signaling may need to be slightly modified to ensure that the logical description between the air interface resources, transport interface resources and resource identity. The embodiment of Figure 5 3 illustrates a step forward.

When performing normal speech generation routines and generating description information, the control unit transmits an acknowledgment signaling message to the first access unit IFU1 (step 3-5). The acknowledgment comprises a new generated connection identifier such that the access unit can later associate with it the transport communication resource used for the connection (e.g., PCM time slots). The first interface unit IFU1 transmits an acknowledgment message via the transmission interface to the base station (step 3-6). The base station preferably converts the information into an air interface interface and normally sends an acknowledgment message (step 3-7) to the first mobile terminal.

In conventional TDM matrix implementations, accounting for switch call control functions generally includes maintaining list descriptors between PCM slots or sub-slots in the input ports and the output ports. By using the logical resource identity described above, which is not affected by the type of communication resource, together with the logical connection ID 20, the straight-line connection-to-channel logging can be continued in the same manner. Regardless of the transition state of the network, the stored information remains consistent, and the actions using and / or affecting the recorded information are simple. The use of the connection ID and resource identity thus distinguishes the accounting of call control functions from the characteristics of the actual physical resources.

In addition, the similarity in accounting achieved through resource identity enables the utilization of many algorithms and practices derived from a conventional system, which significantly reduces the design testing effort associated with the transition period. The mapping between logical re-30 resource identities and physical communication resources can be maintained separately, and the mapping accuracy is automatically verified and updated for routing purposes based on basic signaling functions in various i functional situations. j

Because the control unit does not directly control the switching field, and the switch-35 tag itself does not recognize the resource identity, for full functionality

the control units and the interface units of the device according to the invention must use I

10 shooting information in a specific way during the connection. In the following, this particular way of using the imaging information will be discussed in more detail.

After the call setup and the generation of the imaging information, the control unit generates and transmits (steps 3-8 and 3-9) packets comprising the imaging information and transmits these packets via an Ethernet field to at least the access units whose addresses are included in the imaging information. To simplify the distribution phase, the imaging information may be transmitted by default to all access units and some or all other relevant exchange units. The interface units store the received imaging information 10 for further use.

The speech frames of the first speech unit of the call of the first mobile terminal MT1 are conveyed (3-10) to the base station over the air interface in a time slot, and transmitted (3-11) from the base station in a predetermined PCM sub-slot to the first access unit IFU1. The access module 15 of the embodiment recognizes the PCM sub-slot and is able to determine (3-12) corresponding imaging information received from the control unit. For example, when an access unit identifies information coming from a PCM slot, it may associate a specific resource identity with it. The description information enables the access unit to determine the corresponding connection ID and the addresses of other access units 20 involved in the call. On the other hand, if the access unit recognizes the information coming in the PCM sub-timeslots, it can associate it with a specific connection ID and, based on the mapping information, can determine the corresponding resource identity and other access units involved in the call.

Amplification of speech frames is necessary, for example, for group communication and for recording individual or group communication. In the embodiment of the invention, the amplification takes place in two steps, amplification to the access units and amplification to the access units.

As an example of the first step, the first access unit IFU1 determines (step 3-15) from the mapping information all other access units requested in the call, generates packets comprising one or more speech frames and a connection identifier for all other relevant access units, appends to the generated packets transmits these through the switching matrix to the interface units. Thus, in the case used as an embodiment, the first access unit IFU1 delivers the packet (step 3-16) to the second access unit concerned, the second access unit IFU2.

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It should be noted that these steps may overlap. For example, earlier execution of the second step occurs when the first access unit IFU1 copies one or more speech frames from the incoming PCM sub-time slot 5 to the outgoing PCM sub time slot and thus transmits the speech back to the speaking party (steps 3-13 and 3-14). This can occur before, during, or after the second step.

Based on the connection ID, the second interface unit IFU2 is able to determine (step 3-17) one or more resource identifiers, and thus Vasto provides one or more slots of the PCM under its control. Upon receipt of the speech frame / frames containing packet, the second access unit IFU2 copies the received TETRA speech frame or frames to respective PCM sub-slots for transport to base stations BS2, BS3 (steps 3-18 and 3-19), which further carry the TETRA speech frames allocated to over the mobile terminal MT2 and MT3 (Steps 3-20 and 3-21).

Thus, two-stage amplification, comprising the distribution of imaging information and the actual data frames within the receiving interface unit and the respective interface units, enables the amplification of group communication data streams at hardware and software layers very close to external use and thus significantly optimizing resource utilization. In addition, the mainstream of digital exchanges is designed with individual communication in mind without the need for duplication of information for group communication. The proposed two-phase solution enables the use of standardized mainstream switching fields and back-end solutions, since the additional functionality required for data replication can be implemented on the outer layer of the exchange, i.e., the access units, and essentially separately controllable imaging functionality on the control unit. The ability to use mainstream elements enables lower equipment design, implementation, testing, and maintenance costs, and thus affects both system investment and operating costs.

In the following, let us assume that the second access unit IFU2 was upgraded to implement IP transfer to base stations BS2 and BS3. Generally, this means that the physical communication resources associated with IFU2 resource identifiers would correspond to a specified destination and source address combination that is applicable to the IP network over which the connections are made. During the upgrade, the connection to the resource ID should be updated to the control unit and to 12 IFU2, respectively. However, in the embodiment of the invention, the resource identity remains in the same form as in the previous Time Division Multiplexed (TDM) transmission case. As neither of the steps required for routing the audio frames in the center (distribution of description information and routing / duplication of the audio frames) requires information about the characteristics of the actual physical resource, no further changes are required to the basic operation of the center. The call control may continue to distribute the picture information using connection identity, resource identity, and MAC addresses to all access units or all relevant access units, and the access units may continue transmitting voice frames and, if necessary, replicating to another relevant interface without even needing to know.

Figure 4A shows another exemplary element structure in the TETRA communication system used in the embodiment of Figures 1 and 2 and its digital switchgear. FIG. 4A illustrates the state of operation of FIG. 3A after one of the three mobile terminals, the other mobile terminal MT2, originally located under the second base station BS2, moves to another cell. In the example of Figure 4A, the second mobile terminal is moved to the same cell as the first mobile terminal, but of course the new base station could be any base station 202 available to the second mobile terminal MT2.

Figure 4B shows a signaling diagram illustrating an example associated with a handover situation, practically continuing the signaling diagram of Figure 3B. Step 4-1 illustrates air interface signaling between the second mobile terminal and the second handover base station. At some point, either the new or the old base station informs the exchange (step 4-2) of the change concerning the air interface resource allocated to the call. In the example of Figure 4B, information on old and new air interface channels is provided by the old base station, i.e., the second base station BS2, thus, the signaling message is conveyed to the second interface unit 30 which transmits it to the control unit (step 4-3). The control unit determines a new resource identity corresponding to the new ifmar interface channel allocated to the second mobile station MT2 at the first base station BS1 and the access unit IFU1 which is responsible for the transmission resource corresponding to the air interface channel. The control unit provides new updated mapping information 35 comprising a connection identifier, original resource identifiers associated with the air interface channels of the first and third mobile terminal devices MT1, MT3, which do not change handoff, and a resource associated with the new second mobile terminal device MT2. Further, the updated description information comprises a MAC address of a first access unit IFU1, which is now responsible for the first and second third mobile communication terminals, and a MAC address of the second access unit IFU2, which is still responsible for the third mobile communication terminal MT3.

In response to the aforementioned change in imaging information, the control unit distributes the updated imaging information to at least the access units 1FU1, IFU2, involved in communication (steps 4-5 and 4-6). After the mapping-10 information has been distributed, the control unit may send (step 4-7) an acknowledgment message to the second interface unit IFU2, which may forward the message to either the new or the old base stations BS1 and BS2, or both. In the example of Figure 4A, an acknowledgment message is transmitted (step 4-8) to the new base station BS1 of the second mobile terminal MT2. This acknowledgment message can be considered essential for handoff 15, so that only after confirmation from the exchange, the base station acknowledges (step 4-9) the procedure decision for the handoff handset.

When the second mobile terminal MT2 now supplies (step 4-10) one or more TETRA audio frames to the first base station, the first base station transmits information to the first access unit 1FU1 in a given PCM sub-slot. According to the invention, the first access unit IFU1 determines, based on the mapping information, the resource identity associated with the PCM sub-time slot and amplifies the audio frame (s) to communication resources corresponding to the original resource identity and any resource IDs in its response. In the example of Figure 4A, the voice frame or voice frames are amplified into PCM channels between the first access unit IFU1 and the first base station BS1, and the base station is then able to transmit (steps 4-13 ... 4-16) the audio frames to the first and second mobile terminals. Further, the first access unit IFU1 30 is able to deduce from the updated description information that a packet comprising the audio frame or voice frames and the connection ID must be produced and transmitted (step 4-17) over the switching field to the MAC address of the second access unit IFU2. Upon receipt of the packet, the second interface unit IFU2 is able to transmit the audio frame or audio frames over a suitable PCM sub-slot to a third base station which transmits the audio frame or audio frames to the third mobile device MT3 over a corresponding time slot.

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The procedure shown in Fig. 4B shows that the proposed solution works accurately and efficiently even when switching hands. In addition, the latest routing information is already available for switching operations, either if the handover is from a base station using PCM transmission to a base station whose transmission connections comprise an IP network portion. Similarly, if the new participant MT4 operating under the second base station BS2 joins the group call, the mapping information would only need to be updated to include the air interface channel resource identity in the MT2e, and re-allocated to the relevant interface units IFU1 and IFU2. Steps 4 to 10 to 4 to 19 would be very similar to those shown in Figure 4B, but in step 4 to 18, the second access unit IFU2 would also amplify, based on the last mapping information, to a transfer resource corresponding to the MT4 resource identity.

For some use events, one of the participants could also be on 15 public telephone networks. To this end, as mentioned above, the exchange comprises an additional network interface unit IFUp, which comprises a device and routines for performing TETRA speech coding and decoding, and A-law encoding and decoding for converting information into a PCM format used in a public telephone network. The communication resource at the user end and per access unit 20 is in this case the full A-iaw coded PCM slot. Figure 5A shows a functional situation similar to that of Figure 3A, but the UT 1 participates in a group call from the public telephone network side.

Fig. 5B shows a signaling diagram illustrating the exemplary kinetic sequence associated with the group call of Fig. 5A. Steps 5-1 to 5-6 correspond directly to steps 3-1 to 3-6 and are not repeated here. However, the mapping information produced in the control unit in step 5-4 also comprises a resource identity corresponding to the PCM resource allocated to the UT1 and the MAC address 30 of the public switched telephone access unit IFUp. Thus, in step 5-7, the control unit also distributes the description information according to the invention to the public telephone network interface unit IFUp. For the sake of clarity of description, the previously described steps related to acknowledgment from the control unit to the mobile terminal are not shown in Figure 5B.

Upon detecting transmitted information (steps 5-8 ... 5-9) from the first mobile terminal MT1 in the associated PCM sub-slot, the first access unit IFU1 checks (step 5-10) the control unit for receiving! 15 shooting information. In the first amplification step, the first access unit IFU1 produces packets comprising the received audio frame or received audio frames, provides them with the MAC address tag provided in the description information, and forwards the packets to the second access unit IFU2 and the IFUp of the public telephone network. In a second step, the second access unit uses the connection identity to determine (step 5-15) the resource resources associated with the call, and amplifies the voice frame or voice frames to the second MT2 and the third MT3 for transport. Similarly, the IFUp of the public switched telephone network uses the connection identity to determine the resource identities associated with the call (step 5-20) and, based on the resource identity, determines the correct PCM time slot or slots for transporting the audio frame or audio frames to the user terminal.

The proposed solution is not only insensitive to the interface features but also to the type of ultimate communication resource at the user end.

15 The proposed dual entry control of call control and routing information, and two-step data amplification in access units, thus provides a virtual transit functionality that can be used to implement data flow switching from different types of users and using different communication and transmission technologies.

In an embodiment, the inventive idea is utilized to recover from a defect 20. Such a failure can occur, for example, in the transmission or in the functional unit of the device itself. Fig. 6A shows an exemplary structure of the elements of the second Fig. 3A, but in this case the transmission between the first access unit IFU1 and the first base station BS1, as well as the transmission between the second access unit IFU2 and the second base station BS2 is TDM based is package-based. However, the second base station BS2 has a secondary IP bearer connection to the exchange via the third access unit IFU3.

FIG. 6B shows a signaling diagram illustrating an exemplary procedure associated with a failure situation in an internal transmission link of another base station BS2 en-30. The procedure time out from an arbitrary time during an ongoing call when the first mobile terminal MT1 transmits (step 6-1) to the first base station BS1 speech information in the air interface slot, and the first base station BS2 transmits (step 6-2) information to the first access unit. At present, the second access unit 35 detects (step 6-3), for example, a system-level diagnostic and alarm system notification that reports an error in the primary transmission line between the second access unit and the second base station.

According to the invention, the second access unit IFU2 checks if a secondary transmission is available, and when it detects that a secondary transmission is available, it informs (step 6-4) the situation to the control unit and requests that the secondary route 5 be used. The control unit updates (step 6-5) the resource identity to the IP communication resource of the third interface unit IFU3 used by the MT2 air interface channel. The control unit generates the description information, updates the packets, and forwards them to the appropriate IFU1, IFU2 and IFU3 interfaces (steps 6-6 to 6-8). In a first step, the first access unit IFU1 generates (step 6-10 9) a packet comprising the received audio frame or frames, appends to it the MAC address provided by the third access unit in the updated description information, and forwards (step 6-12) the packet to the third access unit IFU3. . In a second step, the first access unit IFU1 provides a voice frame or voice frames for transport (steps 6-10 and 6-11) to the first 15 mobile terminals MT1 and the third access unit IFU3 amplifies the audio frame or voice frames. The first packet is conveyed (steps 6-15 and 6-16) to the second mobile terminal MT2 via the secondary IP transmission line of the second base station, and the second packet is conveyed (steps 6-13 and 6-14) to the third mobile terminal MT3 via the third base station BS3.

The solution according to the invention thus provides a simple and straightforward way to reconnect and thus recover from a failure in transmission. The same principle can also be used to recover from a failure at the exchange interface unit. For example, with reference to Fig. 6A, instead of the fault being transmitted, the second IFU2 interface unit could be identified as faulty. The procedure shown in Fig. 6B would be applicable substantially as such even in this situation. The control unit would detect (step 6-3) of course the error message and the information about the available secondary route should then be available to the control unit itself, 30 The packets transported within the exchange change according to the application. In the foregoing embodiments, the switching matrix is preferably an Ethemet field and the packets used are thus Ethernet frames. When the packet contains speech data, the payload may comprise at least one, but preferably includes j two TETRA coded audio frames (8Kbit / s, 30 ms). 64 kbit, 30 | can be used for connections to the public switched telephone network 35 and other such connections ms PCM audio coded audio frames. Relatively long data blocks 17 are used, which also have a structure in the PCM transmission on the basis of which the start and end of the block can be inferred. This makes block synchronization much less critical than prior art technologies (such as the recommended 1-TDM for ATCA), since a limited number of additional bits between blocks do not interfere with operations.

In the above embodiments, the base station can operate traditionally without being aware of the logical operators used in the switching and management architecture. Alternatively, the base station may also be arranged to operate using these operators. FIG. 7 illustrates a reference structure of 10 base stations in a communication system used as a pattern embodiment. The base station includes a control unit 710, an element which essentially comprises an arithmetic logic unit, a plurality of special registers and control circuits. The processor unit may be implemented as a single integrated circuit or as a combination of several integrated circuits. The base station also comprises an air-15 interface communication unit 720 provided with a receiving unit 722 for receiving information from a primary access type interface and processing it to be provided to the control unit 710, and a transmitting unit 724 for receiving information from the control unit 710 and processing it via an IT interface. The base station also comprises a network 20 communication unit 730 provided with a receiving unit 732 for receiving information from the switching and management general structure and processing it to be provided to the control unit 710, and a transmitting unit 734 for receiving information from the control unit 710 and processing it for transmission and switching. Implementation of such communication units 25 is well known to those skilled in the art. The control unit 710, the airborne interface communication unit 720, and the network communication unit 730 are electrically interconnected to enable the systematic operation of the received and / or stored information in accordance with predetermined, substantially programmed base station processes. In the solutions of the invention, the operations include functions for implementing the functions of the base station i illustrated in FIG. 8. f

FIG. 8 shows a signaling diagram illustrating an exemplary procedure associated with call setup and speech unit operations in the base station used as an embodiment of FIG. 7. Procedure 35 begins when the mobile terminal MT registered in the base station BS initiates a call by sending (step 8-1) a connection request to the base station {18}. The base station BS transmits (step 8-2) the request switching and management general structure SwMI. During call setup signaling, as described above, the control unit in the switching device provides (step 8-3) image information for the call. More specifically, the control unit generates a connection ID for the call. In addition, the control unit determines the communication resource and air interface channel allocated to the call transmission and associates these with the logical operator with the resource identity. The control unit may receive information from the air interface channel implicitly about the content of the connection request, or the base station may be arranged to refer to each of its available air interface-10 channels with a unique identifier and explicitly provide that identifier to the control unit as soon as the air interface channel is allocated.

Upon completion of the connection set-up procedure, SwMI sends (step 8-4) an acknowledgment message containing the connection ID and the resource identity associated with the call. The base station BS provides (step 8-5) a successful connection 15 to the mobile terminal, but does not necessarily include a connection identity and a resource identity for acknowledgment.

Upon completion of the connection set-up, the mobile terminal MT1 may transmit (step 8-6) uplink audio information normally in the air interface time slots. The base station receives the information, maps it to the resources of the transport interface re-20 (e.g., PCM sub-slots or IP packets), and preferably includes the connection ID and resource identity associated with the call in the resource utilization load of the transport interface (step 8-76). The interface unit of the switching device, which receives (step 8-8) the message, can then map the incoming information to the correct mapping information and thus the addresses of the respective interface units based on the logical operators.

Correspondingly, the payload message of the transfer interface that arrives (step 8-9) to the base station BS now includes the connection ID and the resource identity associated with the call. The base station BS may thus map the incoming information to the correct air interface channel based on the logical operators (step 8-10) and transmit the message to the mobile terminal (step 8-11).

During any changes caused by the mobility of the terminal equipment, signaling steps 8-1 to 8-5 are repeated, but in that case the messages are related to a specific mobility management function, for example a change of a base station cell. ! In one aspect, the invention provides a computer program product which encodes a command program computer program to execute a series of computer functions 19 in a control unit or interface unit of a switching device.

In another aspect, the invention provides a computer program distribution means that is computer readable and encodes a command program computer program for executing a computer procedure sequence on a control unit or interface unit of a switching device.

The distribution medium may include a computer readable medium, a program recording medium, a recording medium, a computer readable memory, a computer readable software distribution package, a computer readable signal, a computer readable communication signal, and a computer readable software program.

It will be obvious to a person skilled in the art that as technology advances, the basic idea of the invention can be implemented in many different ways. For example, more than one service view can be defined for one service. Thus, some pages can be linked to one service view and some pages to another view, so that different types of news may have a slightly different appearance. The invention and its embodiments are thus not limited to the examples described above, but may vary within the scope of the claims.

j 5

Claims (43)

A device comprising: a plurality of functional units, which units include interface units (20, 21, 22, 23) for connecting one or more transmission communication resources to the device; a control unit (25) for controlling a connection to which at least a separate allocable communication resource is allocated at the user end and a transfer communication resource; a switching matrix (26) for coupling the packets of the devices of the device 10, characterized in that: the controller (25) is arranged to maintain resource identity information, a resource identity associating a transmission communication resource with a separate allocable communication resource in the user end; the controller (25) is arranged to generate for the connection mapping information which comprises at least one connection identity, a resource identity associated with the connection identity, and addresses of the interface units connecting the communication resources allocated for the connection; and the controller (25) is arranged to distribute the mapping information at least to the interface units whose address is included in the mapping information. 2. Device according to claim 1, characterized in that the control unit (25) is further arranged to detect during the connection a change in at least a separate allocable communication resource at the user end; to transform the change into! a change in the mapping information; generating updated mapping information for the connection; to distribute the updated mapping information at least 30 to the interface units connecting the communication resources allocated for the connection. j Device according to claim 1 or 2, characterized in that a transmission communication resource is connected to the device in accordance with a communication protocol and another transmission communication resource is connected to the device according to another, different communication protocol, and the resource identity is transparent to a device. communication protocol used in the interface. 4. Device according to any one of claims 1, 2 or 3, characterized in that at least one separately allocable communication resource at the user end is an air interface channel allocated for the connection. Device according to any of claims 1-4, characterized in that the interface unit (20) is arranged to maintain mapping between a communication resource and a communication resource identity received in the last mapping information from the controller (25); and, in response to the reception of information via a transmission communication resource, determine the communication resource identity and derive from the mapping information addresses of the other interface units involved (21). Device according to claim 5, characterized in that the boundary cutter unit (20) is arranged to receive a packet from the coupling matrix (26); determining from the resource identity the transmission communication resource allocated to the connection and conveying the information to the transmission communication resource. Device according to any of the preceding claims, characterized in that the switching matrix (26) and the device units are arranged to exchange packets in Ethernet frames. Device according to any of the preceding claims, characterized in that at least one interface unit (IFU1) transmission communication resource corresponds to a time slot of pulse code modulation or a part-time slot of pulse code modulation. Device according to any one of the preceding claims, characterized in that at least one interface unit (IFU2) transmission communication resource corresponds to a packet transmission resource for a combination of Internet Protocol (IP) compatible call and call addresses. Device according to any of the preceding claims, characterized in that at least one (IFUP) of the device interface units is arranged to connect to the PSTN network and at least one interface unit's transmission communication resource corresponds to an interval of A-Jaw coded pulse coded pulse code. Device according to any of the preceding claims, characterized in that the control unit (25) is arranged or detects a malfunctioning element in the section between the coupling matrix and the base station; 5 controlling whether a bypass route exists; generating updated mapping information for the connection, where the resource identity and / or addresses correspond to the bypass route; and distributing the updated mapping information to the eating man the interface units connecting the communication resources allocated for the connection. 12. Device according to claim 11, characterized in that the faulty element is an interface unit. 13. Device according to claim 11, characterized in that the faulty element is the transmission communication resource according to a communication protocol and the bypass route corresponds to the transmission communication resource according to another, different communication protocol. 14. Interface unit (20), which is adapted to connect an alternate Hera transmission communication resources to a switching device (104); characterized in that the interface unit is arranged to receive mapping information from the switching unit controller (25) which comprises at least one connection identity, a resource identity associated with the connection identity and addresses of the interface units that connect to the communication resources allocated for the connection; and routing information between the transmission communication resources of the coupler and a coupling matrix (26) on the basis of the latest; the mapping information received from the controller of the coupling device. Interface unit (20) according to claim 14, characterized in that a transmission communication resource is connected to the device (104) in accordance with one communication protocol and another transmission communication resource is connected to the device according to another, different communication protocol, and the resource identity is Transparent for a communication protocol used in the interface. Interface unit according to any of claims 14 or 15, characterized in that the interface unit (20) is arranged to maintain mapping between a communication resource and a communication resource identity received in the last mapping information from the controller; in response to receiving information through a transmission communication resource, determining the communication resource identity and deriving from the mapping information the addresses of the other interface units involved (21); generating packets, viika encompasses the received information, and viika is addressed to addresses of other interface units involved (21); and passing the packets to the switching matrix. The interface unit according to claim 16, characterized in that the offset interface unit is arranged to receive a packet from the switching matrix (26); to determine from the resource identity the transmission communication resource allocated for the connection and convey the information to the transmission communication resource. Interface unit according to any of the preceding claims 14-17, characterized in that the interface unit is arranged to exchange packets in Ethernet frames. 19. Interface unit according to any of the preceding claims 20-17, characterized in that the interface communication transmission resource corresponds to a time slot of pulse code modulation or a part-time slot of pulse code modulation. Interface unit according to any of the preceding claims 14-17, characterized in that the interface communication transmission resource corresponds to a packet transmission resource for a combination of Internet Protocol (iP)-compatible source and message addresses. 21. An interface unit according to any of the preceding claims 14-17, characterized in that the interface unit is arranged to connect to the PSTN network and its transmission communication resource corresponds to an interval of A-law-encoded pulse code modulation. A control unit (25) for a switching device (104), said control unit j (25) being arranged to control a connection, to which is allocated at least a separately allocable communication resource at the user end and a transfer communication resource for the switching device (104); characterized in that: a. the controller (25) is arranged to maintain resource identity information, wherein a resource identity associates a transfer communication resource with a separately allocable communication resource at the user end; the controller (25) is arranged to generate mapping information for the connection which includes at least one connection identity, a resource identity associated with the connection identity, and addresses of the interface units that connect to the communication allocated resources; and the controller (25) is arranged to distribute the mapping information at least to the interface units whose address is included in the mapping information. Control unit according to claim 22, characterized in that the control unit (25) is further arranged to detect during the connection a change in at least a separately allocable communication resource at the user end; Converting the change into a change in the mapping information; generating updated mapping information for the connection; to distribute the updated mapping information at least to the interface units connecting the communication resources allocated for the connection. Control unit according to claim 22 or 23, characterized in that a transmission communication resource is connected to the switching device (104) in accordance with one communication protocol and another transmission communication resource is connected to the device in accordance with another, different communication protocol, and the resource identity is translucent for a communication protocol used in the interface 25. A control unit according to any one of claims 22, 23 or 24, characterized in that at least one separately allocable communication resource at the user end is an air interface channel allocated for the connection. Control unit according to any of claims 22-25, characterized in that the control unit (25) is arranged to exchange packets in Ethernet frames. Control unit according to any of the preceding claims 22-26, characterized in that at least one interface unit (20) transmission communication resource corresponds to a time slot of pulse code modulation or a part-time slot of pulse code modulation. 28. Controller according to any of the preceding claims 22-26, characterized in that at least one interface unit's transmission communication resource corresponds to a packet transmission resource for a combination of Internet Protocol (1P) compatible source and message addresses. Controller according to any of the preceding claims 22-26, characterized in that at least one of the device interface units (IFUp) is arranged to connect to the PSTN network and at least one interface unit's transmission communication resource corresponds to an interval! of A-law coded pulse code modulation. Device according to any one of claims 22-26, characterized in that the control unit is arranged to detect a faulty element in the section between the coupling matrix and the base station; checking whether a bypass route exists; generating updated mapping information for the connection, where the resource identity and / or addresses correspond to the bypass route; and to distribute the updated mapping information to at least the interface units (IFU3) that connect the communica- tion resources allocated for the connection. Control unit according to claim 30, characterized in that the faulty element is an interface unit (IFU2). The controller according to claim 30, characterized in that the faulty element is the transmission communication resource according to one communication protocol and the bypass route corresponds to the transmission communication resource according to another, different communication protocol. 25 33. A method of coupling information between a plurality of functional units, which units comprise interface units for connecting one or more transmission communication resources to the device; a controller for controlling a connection to which is allocated at least a separately allocable communication end at the user end and a transfer communication resource; and a switching matrix for coupling packets between the device units, characterized in that resource identity information is maintained in the method, associates a transmission communication resource with a separately allocable communication resource at the user end; mapping information (3-4) is generated for the connection, mapping information which includes at least one connection identity, a resource identity associated with the connection identity, and addresses of the interface units that connect the grain communication resources allocated for the connection; and (3-8, 3-9) the mapping information is distributed at least to the interface units whose address is included in the mapping information. 5 34. Method according to claim 33, characterized in that during the connection, a change in at least a separate allocable communication resource is detected at the user end; the change is converted to a change in the mapping information; updated mapping information is generated for the connection; At least the updated mapping information is distributed to the interface units that connect the communication resources allocated for the connection. A method according to claim 33 or 34, characterized in that mapping is maintained in the interface unit of the coupling device between a communication resource and a communication resource identity received in the last mapping information from the controller; and in response to the receipt of information via a transmission communication resource (3-17), the communication resource identity is determined and derived from the mapping information addresses of the other interface units involved. 36. A method according to claim 35, characterized in that a packet is received from the switching matrix; from the resource identity, (3-17), the transmission communication resource allocated for the connection is determined and the information is conveyed (3-18 - 3-21) to the transmission communication resource. 37. A method according to any one of the preceding claims 33-36, characterized in that a faulty element is detected (6-3) in the section between the coupling matrix and the base station; \ in the control unit (6-4) checks whether a bypass route exists; in the controller unit (6-5) for the connection, updated mapping information is generated, where the resource identity and / or addresses correspond to the bypass route; and the updated mapping information is distributed (6-6 - 6-8) to at least the interface units connecting the communication resources allocated for the connection. 38. Base station (108), which is arranged to convey information between air interface communication resources terminating in a mobile terminal (114) and transmission interface communication resources terminating in a switching device (104), characterized in that the base station (108) is arranged to receive in connection with a connection establishment from the switching device a resource identity that associates a transmission communication resource with an air interface communication resource, combined with a connection identity generated by the switching device; 10 to use at least during the call the resource identity and the connection identity for communication with the switching device. 39. Base station according to claim 38, characterized in that the base station is arranged to use the resource identity and the connection identity in communication with the switching device by including the resource identity and the connecting identity in which message is sent as the switching device. A tele-communication system comprising a base station (108) according to either of claims 38 or 39. 41. Computer software product, which encodes a computer process containing commands for performing a computer process for coupling information between a plurality of functional units, which units include interface units for connecting one or more transmission communication resources to the device; a control unit for controlling a connection, to the bay, at least a separate allocable communication resource is allocated at the user end and a transfer communication resource; and a switching matrix for connecting packets between the devices of the device, said process comprising maintaining resource identity information, wherein a resource identity associates a transmission communication resource with a separately allocable communication resource at the user end; Generating mapping information for the connection, the mapping information information includes at least one connection identity, a resource identity associated with the connection identity, and addresses of the interface units connecting the communication resources allocated for the connection; and distributing the mapping information at least to the interface units whose addresses are included in the mapping information. 42. Computer program distribution medium, which can be read with a computer and which encodes a computer process containing commands to perform a computer process for coupling information between a plurality of functional units, which units comprise interface units for connecting one or more transmission communication resources to the device; a control unit for controlling a connection, to the bay, at least a separately allocable communication end at the user end and a transfer communication resource are allocated; and a switching matrix for switching packets between device units, said process comprising maintaining resource identity information, wherein a resource identity associates a transmission communication resource with a separate user-accessible communication resource; generating mapping information for the connection, the mapping information includes at least one connection identity, a resource identity associated with the connection identity, and addresses of the interface units connecting the communication resources allocated for the connection; and distributing the mapping information at least to the interface units whose addresses are included in the mapping information. The distribution medium of claim 42, which comprises a medium readable by computer, a program storage medium, a recording medium, a computer readable memory, a computer readable software distribution package, a readable signal with computer, a telecommunication signal readable by computer and a compressed software package readable by computer.