EP0891681A1

EP0891681A1 - Control of the change of telecommunications channels in a dect-specific rll/wll partial system bound to an isdn-system

Info

Publication number: EP0891681A1
Application number: EP97921602A
Authority: EP
Inventors: Horst Flake; Martin Kordsmeyer
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 1996-04-04
Filing date: 1997-04-03
Publication date: 1999-01-20
Also published as: BR9708531A; AU2762597A; US6584114B1; CA2250838A1; ID16514A; PL329638A1; PL183294B1; JP3099968B2; JP2000505634A; CN1215538A; WO1997038546A1

Abstract

In a partial telecommunications system bound to a telecommunications system as a local information transmission loop, in particular a DECT-specific RLL/WLL partial system bound to an ISDN-system, a change must be made from one telecommunications channel, for example the Cf channel defined in the DECT standard, to another telecommunications channel, for example the Cs channel defined in the DECT standard, when transmitting system information in the local information transmission loop. This channel is initiated and carried out preferably by interrupting for a short time the transmission of information in the partial telecommunications system, then by resuming the transmission of information.

Description

description

CHANNEL CHANGE CONTROL IN AN ISDN SYSTEM INCLUDED DECT-SPECIFIC RLL / WLL SUBSYSTEM

In message systems with a message transmission path between a message source and a message sink, transmitting and receiving devices are used for message processing and transmission, in which

1) message processing and message transmission can take place in a preferred transmission direction (simplex operation) or in both transmission directions (duplex operation),

2) the message processing is analog or digital,

3) the message transmission over the long-distance transmission link is wired or on the basis of various message transmission methods FDMA (Frequency Division Multiple Access), TDMA (Time Division Multiple Access) and / or CDMA (Code Division Multiple Access) - e.g. according to radio standards such as DECT, GSM, WACS or PACS, IS-54, PHS, PDC etc. [cf. IEEE Communications Magazine, January 1995, pages 50 to 57; D.D. Falconer et al: "Time Division Multiple Access Methods for Wireless Personal Communications"] takes place wirelessly.

"Message" is a superordinate term that stands for both the meaning (information) and the physical representation (signal). Despite the same meaning of a message - ie the same information - different signal forms can occur. So z. B. a message relating to an object (1) in the form of an image,

(2) as a spoken word,

(3) as a written word, (4) transmitted as an encrypted word or image. The type of transmission according to (1) ... (3) is usually characterized by continuous (analog) signals, while the type of transmission according to (4) usually produces discontinuous signals (e.g. impulses, digital signals).

Starting from this general definition of a message system, the invention relates to a method for controlling the change of telecommunication channels of a telecommunication subsystem integrated in a telecommunication system as a local message transmission loop - in particular a DECT-specific RLL / WLL subsystem integrated in an ISDN system (Radio Local Loop / Wireless Local Loop) - according to the preamble of claim 1.

FIGURE 1 shows, starting from the publications "Nachrichten¬ Technik Elektronik, Berlin 45 (1995) Issue 1, Pages 21 to 23 and Issue 3 Pages 29 and 30" and IEE Colloquium 1993, 113; (1993), Pages 29/1 - 29 / 1; W.Hing, F. Halsall: "Cordless access to the ISDN basic rate service" based on a DECT / ISDN intermediate system DIIS according to the ETSI publication prETS 300xxx, version 1.10, September 1996 a " ISDN <→ DECT-specific RLL / WLL "telecommunications system IDRW-TS (Integrated Services Digital Network <-» Radio in the Local Loop / Wireless in the Local Loop) with an ISDN telecommunications subsystem I-TTS {cf. Publication "Kommunikationstechnik Electronics, Berlin 41-43, Part: 1 to 10, Part: (1991) Issue 3, Pages 99 to 102; T2: (1991) Issue 4, pages 138-143; T3: (1991) Issue 5, pages 119 to 182 and Issue 6, pages 219 to 220; T4: (1991) issue 6, pages 220 to 222 and (1992) issue 1, pages 19 to 20; T5: (1992) Book 2, pages 59 to 62 and (1992) Book 3, pages 99 to 102; T6: (1992) Issue 4, pages 150 to 153; Tl: (1992) Issue 6, pages 238 to 241; T8: (1993) Issue 1, pages 29 to 33; T9: (1993) issue 2, pages 95 to 91 and (1993) issue 3, pages 129 to 135; T10: (1993) Book 4, pages 187 to 190; "] and a DECT-specific RLL / WLL telecommunications subsystem RW-TTS.

The DECT / ISDN Intermediate System DIIS or the RLL / WLL telecommunications subsystem RW-TTS is preferably based on a DECT / GAP system DGS [Digital Enhanced (formerly: European) Cordless Telecommunication; see. (1): Nachrichten¬ technik electronics 42 (1992) Jan./Feb. No. 1, Berlin, DE; U. Pilger "Structure of the DECT standard", pages 23 to 29 in connection with the ETSI publication ETS 300175-1 ... 9, October 1992; (2): Telcom Report 16 (1993), No. 1, JH Koch: "Digital convenience for cordless telecommunications - DECT standard opens up new areas of use", pages 26 and 27; (3): tec 2/93 - Ascom's technical magazine "Paths to universal mobile telecommunications", pages 35 to 42; (4): Philips Telecommunication Review Vol. 49, No. 3, Sept. 1991, RJ Mulder: " DECT, a universal cordless access system "; (5): WO 93/21719 (FIG. 1 to 3 with the associated description)]. The GAP standard (Generic Access Profile) is a subset of the DECT standard, the the task is to ensure the interoperability of the DECT air interface for telephone applications (cf. ETSI publication prETS 300444, April 1995).

The DECT / ISDN Intermediate System DIIS or the RLL / WLL

Alternatively, the RW-TTS telecommunications subsystem can also be based on a GSM system (Groupe Speciale Mobile or Global System for Mobile Communication; see Informatik Spektrum 14 (1991) June, No. 3, Berlin, DE; A.Mann: "Der GSM- Standard - Basis for digital European mobile radio networks ", pages

137 to 152). Instead, within the framework of a hybrid telecommunications system, it is also possible for the ISDN telecommunications subsystem I-TTS to be designed as a GSM system.

In addition, there are further possibilities for realizing the DECT / ISDN intermediate system DIIS or the RLL / WLL telecommunications subsystem RW-TTS or the ISDN Telecommunication subsystem I-TTS, the systems mentioned at the outset and future systems based on the known multiple access methods FDMA, TDMA, CDMA (Frequency Division Multiple Access, Time Division Multiple Access, Code Division Multiple Access) and hybrid multiple access methods formed therefrom .

The use of radio channels (e.g. DECT channels) in traditional line-based telecommunication systems, such as ISDN, is becoming increasingly important, especially before

Background of future alternative network operators without their own complete wire network.

For example, for the RLL / WLL telecommunications subsystem RW-TTS, the wireless connection technology RLL / WLL (Radio in the

Local Loop / Wireless in the Local Loop) e.g. with the integration of the DECT system DS, ISDN services are made available to the ISDN subscriber at standard ISDN interfaces (cf. FIG. 1).

In the "ISDN <→ DECT-specific RLL / WLL" telecommunications system IDRW-TS according to FIG. 1 there is a telecommunications subscriber (user) TCU (Tele-Communication User) with its terminal TE (terminal endpoint; terminal equipment) ) for example via a standardized S-interface (S-BUS), the DECT / ISDN Intermediate System DIIS (first telecommunications subsystem), which is designed as a local message transmission loop and is preferably DECT-specific and is contained in the RLL / WLL telecommunications subsystem RW-TTS ), a further standardized S interface (S-BUS), a network termination NT (Network Termination) and a standardized U interface of the ISDN telecommunication subsystem I-TTS (second telecommunication subsystem) into the ISDN world with the therein available services.

The first telecommunication subsystem DIIS essentially consists of two telecommunication interfaces, one first telecommunication interface DIFS (DECT Intermediate Fixed System) and a second telecommunication interface DIPS (DECT Intermediate Portable System), which are wirelessly connected to each other, for example via a DECT air interface. Because of the quasi-location-bound first telecommunication interface DIFS, the first telecommunication subsystem DIIS forms the local night-time transmission loop defined above in this context. The first telecommunications interface DIFS contains a radio fixed part RFP (Radio Fixed Part), an adapter unit IWU1 (InterWorkmg Dnit) and an interface circuit INC1 (INterface Circuitry) to the S interface. The second telecommunications interface DIPS contains a radio mobile part RPP (Radio Portable Part) and a matching unit IWU2 (InterWorkmg Unit) and an interface circuit INC2

(Interface Circuitry) to the S interface. The RFP fixed part and the RPP radio handset form the well-known DECT / GAP system DGS.

The following general problems exist for a DECT-specific RLL system as a carrier for as many ISDN services as possible in the subscriber line: a) simulation of the ISDN channel structure (D channel and 2 B channels), in the following, special D channel, b) good bandwidth economy; Particularly important for ISDN, since some services already require two DECT channels for the B-channel data rate of 64 kbps, c) minimal technical effort.

Replica of the D channel

Properties of the D channel:

Common signaling channel on the C level (C plane) for all terminal devices TE (terminal endpoint) connected to the ISDN connection. The TE-specific signaling channels to the network are separated by TE-individual addresses TEI (Terminal Endpoint Identifier).

The access mechanism to the D channel ensures the order of the messages individually for each TE. Throughput rate: 16 kbpε

Utilization: depending on many criteria, usually lower than maximum capacity; Traffic jams are possible, but can be quickly dismantled due to the high capacity.

DECT channels:

FIGURE 2 shows, based on the printing, “Nachrichten- technik Elektronik 42 (1992) Jan./Feb., No. 1, Berlin, DE; U. Pilger: "Structure of the DECT standard", pages 23 to 29 in connection with ETS 300 175-1 ... 9, October 1992 "the TDMA structure of the DECT / GAP system TKS. The DECT / GAP system is a hybrid system with regard to the multiple access methods, in which radio messages according to the FDMA principle on ten frequencies in the frequency band between 1.88 and 1.90 GHz are based on the TDMA principle according to FIG. 2 in a predetermined time sequence from the base station RFP to The RPP handset and the RPP handset can be sent to the base station RFP (duplex operation)

Multi-time frame MZR, which occurs every 160 ms and which has 16 time frames ZR, each with a duration of 10 ms. In this time frame ZR, information relating to a C, M, N, P, Q channel defined in the DECT standard is transmitted separately after the base station RFP and handset RPP. Be in a time frame ZR information transmitted for meh ^¬ eral of these channels, the transmission takes place according to a priority list with M>C> N and P> N. Each of the 16 time frames ZR of the multiple time frame MZR is in turn divided into 24 time slots ZS each having a time duration of 417 microseconds ^¬, 12 of which Zeitεchlitze ZS (time slots 0 ... 11) for the Übertragungεrichtung "base station RFP → handset RPP 'and another 12 time slots ZS (time slots 12 ... 23) are intended for the transmission "mobile part RPP → base station RFP". In each of these time slots ZS, information with a bit length of 480 bits is transmitted according to the DECT standard. Of these 480 bits, 32 bits become transmitted as synchronization information in a SYNC field and 388 bits as user information in a D field. The remaining 60 bits are transmitted as additional information in a Z field and as protection information in a "guard time" field. The 388 bits of the D field which are transmitted as useful information are in turn divided into a 64 bit long A field, a 320 bit long B field and a 4 bit long "X-CRC" word. The 64 bit long A field is set is composed of an 8-bit data header, a 40-bit data record with data for the C, Q, M, N, P channels and a 16-bit "A-CRC" word.

Characteristics:

Use of TDMA time slots.

In principle, each time slot uses a C _ε channel (s = εlow) for signaling [C level (C plane) in the DECT standard] and an assigned channel [U plane (U plane) in the DECT standard] for uses the user or user information (throughput: 32 kbps). Throughput of the C ₃ channel: 2 kbps.

The DECT standard also offers other channel structures, e.g. B, a Cf channel (f = almost).

The C _£ channel occupies a time slot.

Throughput of the C _f channel: 25.6 kbps.

FIG. 3 shows on the basis of the OSI / ISO layer model [cf. (1): Unterrichtsblätter - Deutεche Telekom Jg. 48, 2/1995, pages 102 to 111; (2): ETSI publication ETS 300175-1.9, October 1992; (3): ETSI publication ETS 300102, February 1992; (4): ETSI publication ETS 300125, September 1991; (5): ETSI publication ETS 300012, April 1992] em model of the C- Level of the "ISDN <→ DECT-specific RLL / WLL" telecommunication system IDRW-TS according to FIG. 1.

FIG. 4 shows on the basis of the OSI / ISO layer model [cf. (1): Lesson sheets - Deutsche Telekom Jg. 48,

2/1995, pages 102 to 111; (2): ETSI publication ETS 300175-1.9, October 1992; (3): ETSI publication ETS 300102, February 1992; (4): ETSI publication ETS 300125, September 1991; (5): ETSI publication ETS 300012, April 1992] em model of the U-level for voice data transmission of the "ISDN <-> DECT-specific RLL / WLL" telecommunication system IDRW-TS according to FIGURE 1.

Margin porridge tp-Oknnoττne

The C _ε channel structure offers an optimal bandwidth economy for a standard speech connection, since according to FIG. 5 starting from FIGS. 3 and 4 and taking into account the ETSI publications (ETS 300175-1, 10/1992, chap. 7; ETS 300175-3, 10/1992, chapter 4.1; ETS 300175-4, 10/1992, chapter 4) only one transmission path (bearer) - e.g. MBC with the LCNy, LCN1 according to FIGURE 5 - or a connection or a time slot is required.

According to FIG. 5, the use of the Cf channel is based on FIGS. 3 and 4 and taking into account the ETSI publications (ETS 300175-1, 10/1992, chapter 7; ETS 300175-3, 10/1992, chapter 4.1; ETS 300175-4, 10/1992, chap. 4) to a lower bandwidth economy, since the U-plane (U-plane) itself requires a further transmission path (bearer) or an additional connection or a further time slot; ie two transmission paths (bearers) - for example MBC with the LCN2, LCNz and MBC with the LCNy, LCNl according to FIG. 5 - or two connections or two time slots are necessary for a simple voice connection. In addition, in the event that there are two ISDN B-channel connections (voice connections), three transmission paths (bearers) - eg MBC with the LCNx, LCNO, MBC with the LCNy, LCN1 and MBC with the LCNz , LCN2 according to FIG. 5 - or three connections or three time slots are required.

While from the point of view of the channel capacity the use of the C _f channel seems to be expedient, from the point of view of the bandwidth economy the use of the C ₃ channel is expedient.

Regardless of whether the C _f channel or the C ₃ channel is used for the connection establishment (establishment of transmission paths), it must be ensured (see FIG. 5) that at any time from the Cf channel to the C ₃ channel and vice versa can be changed (channel change between channels unequal channel capacity). In addition, due to the possibility that two connections (transmission paths) can be established simultaneously in the ISDN system (2 B channels), it must be ensured that there is a change between a first C ₃ channel and a second C ₃ channel can (channel change between two channels of the same channel capacity).

The object on which the invention is based is to transmit system information in a telecommunications subsystem which is integrated in a telecommunications system as a local night transmission loop, in particular a DECT-specific RLL / WLL subsystem integrated in an ISDN system In the local night transmission loop, switching from one telecommunication channel to another telecommunication channel is easy to control without any influence on the subsystem information usually transmitted to the telecommunication subsystem.

This task is based on the m defined in the preamble of claim 1 by the method in the Characteristic of claim 1 specified features ge solved.

The idea on which the invention is based consists in changing the channel in a telecommunication subsystem, which is integrated in a telecommunication system as a local message transmission loop - in particular a DECT-specific RLL / WLL subsystem integrated in an ISDN system - of the inputs mentioned and outlined Type to control by two commands, a first command designed as a switch command and a second command designed as a switch response.

According to claims 2 and 3, it is advantageous to initiate the channel change in a targeted manner.

According to claim 7, it is particularly advantageous to initiate and carry out the channel change by temporarily interrupting the information or message transmission in the telecommunications subsystem and then resuming the information or message transmission.

This is preferably done - when changing the channel from a DECT-specific C _f channel to a DECT-specific C _ε channel and vice versa or when changing the channel from a first DECT-specific C ₃ channel to a second DECT -specific fi _ε channel according to claims 46 and 47 by an ATTRIBUTE_REQUEST information element integrated in the DECT protocol as a switching command and an ATTRIBUTE_ CONFIRM information element integrated in the DECT protocol as switching response or in accordance with claims 48 and 49 a SUSPEND information element integrated in the DECT protocol as a changeover command and a RESUME information element integrated in the DECT protocol as a changeover response). Further advantageous developments of the invention are specified in the remaining claims.

The first exemplary embodiment of the invention is explained with reference to FIGS. 6 to 10.

FIGS. 6 to 10 show different incentive state diagrams, the possible sequences when changing telecommunication channels of a telecommunication subsystem integrated in a telecommunication system as a local night transmission loop, in particular an RLL / WLL subsystem RW- integrated in an ISDN system. TTS-DIIS, represent.

FIGURE 6 shows, based on FIGURES 1 to 5, a first incentive state diagram, which represents the basic control sequence for a change of subsystem channel.

The first telecommunication interface DIFS is connected on a first transmission path with a first transmission path number LCNx (Logical Connection Number; identifier) through a first subsystem channel C _x to the second telecommunication interface DIPS. In addition, between the first telecommunication interface DIFS and the second telecommunication interface DIPS, there is a further telecommunication connection on a second transmission path with a second transmission path number LCNy (identifier) through a second subsystem channel C _y or alternatively there can be between the first telecommunication interface DIFS and the second one Telecommunication interface DIPS can be set up on a second transmission path with a second transmission path number LCNy through a second subsystem channel C _{y an} additional telecommunication connection.

The relationship LCNx ≠ LCNy applies to the transmission path numbers LCNx, LCNy. The first subsystem channel C _x can be as DECT-specific C _f channel or C _ς channel can be formed. Because of the channel constellations that occur in the DECT-specific telecommunications subsystem RW-TTS, DIIS, the second subsystem channel C _{y is} consequently em C _ε channel or em Cf channel or C ₃ channel. According to FIG. 6, the first subsystem channel C _{x is used} for information transmissions on the C plane (C plane).

In order to set up a transmission path, a DECT-specific first B-field message "BEARER_REQUEST" (cf. ETSI publication ETS 300175-3, October 1992, chap. 7.3.3.2) as a command (COMMAND) and a DECT specific second B-field message "BEARER_CONFIRM" (cf. ETSI publication ETS 300175-3, October 1992, chap. 7.3.3.3) was sent as a response (RESPONSE) (cf. ETSI publication ETS 300175-3, October 1992, chap. 10.5.1.1 to 10.5.1.3). The sending of the first B-field message "BEARTER_REQUEST" is preferably initiated by the second telecommunication interface DIPS (cf. FIGURES 9 and 10 and ETSI publication ETS 300175-3, October 1992, chap. 10.5.1.2 and 10.5.1.3).

Through an analysis of the ISDN "Layer 2" / "Layer 3" messages or the amount of messages transmitted via them (cf. document "Message Technology Electronics, Berlin 41, T2: (1991) Issue 4, pages 138 to 143; ") on the transmission line" ISDN network <--> ISDN subscriber (Terminal Endpoint TE) ", for example, the first telecommunication interface DIFS recognizes the need to change the channel (change from the first subsystem channel C _x to the second subsystem channel C _y ) bring about. The result of the analysis forms the stimulus for the channel change.

A possible first result of this analysis can be, for example, that on the first subsystem channel C _x, preferably for a predetermined period of time, no messages between the first telecommunication interface DIFS and the second telecommunication interface DIPS are transmitted.

A possible second result of this analysis can be, for example, that two transmission paths, each with a C level and a U level, are set up and the transmission path on which the C level is used is to be reduced; consequently a change from the previously active C ₃ channel to be dismantled to the previously inactive C ₃ channel is necessary.

To minimize the effort, it is expedient to carry out the analysis described above in one of the telecommunication interfaces DIFS, DIPS - ∑. B. in an advantageous manner of the first telecommunication interface DIFS - to concentrate and therefore control the second telecommunication interface DIPS [MASTER-SLAVE configuration, in which the first telecommunication interface DIFS is the MASTER and the second telecommunication interface DIPS is the SLAVE]. In this constellation, the first telecommunications interface DIFS always has the option of selecting a DECT channel structure corresponding to the ISDN service (C level and / or U level).

Instead of the first telecommunication interface DIFS, it is also possible to provide the second telecommunication interface DIPS for this. However, this is only possible if it has direct access to the ISDN "layer 3". Alone from the ISDN "layer 2" function, the second telecommunications interface DIPS cannot uniquely map a TE-individual connection with the C level and U level to a corresponding DECT channel structure in all situations.

In the further explanation of the exemplary embodiment, the MASTER-SLAVE configuration described above is used as a basis. With a DECT-specific first DLC message "RECEIVE_READY" sent as an answer (RESPONSE) (cf. ETSI publication ETS 300175-4, October 1992, chap. 7.11.2), the first telecommunications interface DIFS is preferred - after having used it Has recognized the need for a channel change - all unacknowledged (unanswered) information transmitted and completely received on the first subsystem channel C _x according to the HDLC protocol (High level Data Link Control), the so-called I-frames (information package) , confirm (answer) if no further I-frame is sent.

According to the HDLC protocol it is e.g. possible to transmit the information (I-frame) in transmission sequences (windows) and to acknowledge each transmission sequence (each window) separately. In the present case, the information is transmitted, for example, with a window size of k = 3 before acknowledgment. The window size k = 3 means with respect to the above-mentioned I frames that after every third I frame an acknowledgment of the previously transmitted three frames takes place. The following relationship generally applies to window size k:

1 <k <n with n e N

By transmitting a first message

"SWITCHING_REQUEST"., Which can, for example, either be defined in the DECT standard (cf. MAC message "ATTRIBUTES_T._REQUEST" in FIGURES 7 to 10 according to ETSI publication ETS 300175-3, October 1992, chapter 7.2 .5.3.8) or still to be defined in this, the request of the first telecommunication interface DIFS to transfer the transmission of the system information from the first subsystem channel C _x to the second subsystem channel C _{y is} transmitted to the second telecommunication interface DIPS. As mentioned above, the request may have arisen through stimulation or without any impetus. Based on the transmission of this message, the first telecommunication interface DIFS can either - preferably - interrupt its own information transmission on the C level or continue with the transmission of the information on the C level. Interruption here means that the first telecommunication interface DIFS will no longer send any further information for a predetermined period of time. The interruption can take place, for example, before, with or after the transmission of the message.

In addition, the message can be sent at the I-frame boundaries and within an I-frame.

The second telecommunication interface DIPS, with or after receipt of the message "SWITCHING_REQUEST", will preferably delete all incompletely received I frames and, with or after receipt of the message "SWITCHING_REQUEST", it can transmit its own information at the C level, like the first telecommunication interface DIFS , either pause or continue.

In addition, the second telecommunications interface DIPS, in the event that the own transmitter is free, with the DECT-specific first DLC message "RECEIVE_READY" sent as a response (RESPONSE) (cf. ETSI publication ETS 300175-4, October 1992, Chapter 7.11.2) confirm (answer) all unconfirmed (unanswered) information transmitted and completely received on the first subsystem channel C _x according to the HDLC protocol (High level Data Link Control), the so-called I-frame.

As an alternative to the immediate interruption, it is also possible for the second telecommunications interface DIPS to complete the transmission of an I-frame before the interruption. The interruption of the information transmission or the continuation of the information transmission on the first subsystem channel C _x by the second telecommunication interface DIPS preferably takes place between the receipt of the first message and before the transmission of a second message "SWITCHING_CONFIRM", which is again, for example, either in the DECT Defined as standard can be (cf. MAC message "ATTRIBUTES_T._CONFIRM" in FIGURES 7 to 10 in accordance with ETSI publication ETS 300175-3, October 1992, chap. 7.2.5.3.8) or m still to be defined.

The second message "SWITCHING_CONFIRM" corresponds, for example, to the wish of the first telecommunications interface DIFS for a change in the subsystem channel, by confirming it (answered positively).

It is also possible, however, that the second telecommunication interface DIPS, consciously or unconsciously (e.g. by not receiving the first message due to a fault on the radio transmission link) does not correspond to the request.

In the event that the request is deliberately not met, the first message "SWITCHING_REQUEST" is either immediate or indirect, e.g. by specifying a predefined one

Time period for the confirmation of the first message is exceeded, rejected by the second telecommunication interface DIPS (answered negatively).

Otherwise, the first message "SWITCHING_REQUEST" is communicable, e.g. by exceeding a predetermined time for the confirmation of the first message (answered negatively).

In both cases mentioned above, either the first message "SWITCHING_REQUEST" from the first telecommunication interface DIFS is repeated for a predetermined number transmitted or the channel change aborted for an indefinite time.

Due to the transmission of the second message "SWITCHING_CONFIRM", the information transmission is continued on the second subsystem channel C _y . The continuation can preferably take place with or after the transmission of the message.

After or upon receipt of the second message “SWITCHING_CONFIRM”, the first telecommunication interface DIFS will preferably also delete the unconfirmed information transmitted and incompletely received on the first subsystem channel C _x .

Before the information deleted by the first telecommunication interface DIFS and the second telecommunication interface DIPS is retransmitted on the second subsystem channel C _y, subsystem-specific parameters, such as the retransmission counter or timer specific to the DLC layer (see ETSI -Publication ETS 300175-4, October 1992, section 9.2.5.7) and the C _τ package number (see ETSI publication ETS 300175-3, October 1992, section 7.1.2) have been reset.

In addition, a test message which must be confirmed can be transmitted on the second subsystem channel C _y before the information deleted by the first telecommunication interface DIFS and the second telecommunication interface DIPS is transmitted again. The test message is preferably the first DLC message "RECEIVE_READY" sent as a command (COMMAND) (cf. ETSI publication ETS 300175-4, October 1992, chap. 7.11.2) while the confirmation of the Test message is preferably the first DLC message "RECEIVE_READY" sent as a response (RESPONSE) (cf. ETSI publication ETS 300175-4, October 1992, chap. 7.11.2). Both the test message and the deleted information are preferably, in order to achieve rapid synchronization on the second subsystem channel C _y , at the beginning (initial phase of the transmission) with the smallest possible window size according to the HDLC protocol, that is k = 1 , transmitted and then transmitted again with the window size k = 3.

FIGURE 7 is based on FIG 6, a second supply incentive εtandε diagram daε the control sequence for the change from a first subsystem channel C _£ to a second channel Teilsystem¬ _E represents C.

The first subsystem channel Cf is used for information transmission at the C level. The second subsystem channel C _ε is not used for information transmission at the C level. However, the U level is used. The first subsystem channel C _f has a greater transmission capacity than the second subsystem channel C _s .

The first telecommunications interface DIFS recognizes that the first subsystem channel Cf is no longer necessary and sends a first MAC message "ATTRIBUTES_T._REQUEST" (cf. ETSI publication ETS 300175-3, October 1992, chapter 7.2.5.3.8) second telecommunications interface DIPS.

The second telecommunications interface DIPS confirms the first MAC message "ATTRIBUTES_T._REQUEST" by sending a second MAC message "ATTRIBUTES_T._CONFIRM" to the first telecommunications interface DIFS. Thereafter, the second subsystem channel C _{s is used} for information transmission at the C level and the first subsystem channel Cf by transmitting a third MAC message "RELEASE" (cf. ETSI publication ETS 300175-3, October 1992, chapter 7.2. 5.3.13) resolved. FIGURE 8 shows, starting from FIGURE 6, a third incentive state diagram which represents the control sequence for the change from the second subsystem channel C _s to a third subsystem channel C _s .

The second subsystem channel C _s is used for information transmission at the C level. The U level is also used. The third subsystem channel C _ε is not used for information transmission at the C level. However, the U level is used. The second subsystem channel C _£ has the same transmission capacity as the third subsystem channel C _s .

The first telecommunications switching point DIFS recognizes that the second subsystem channel C _{s is} no longer necessary and sends the first MAC message “ATTRIBUTES_T._REQUEΞT” (cf. ETSI publication ETS 300175-3, October 1992, chap. 7.2.5.3.8) to the second telecommunications interface DIPS.

The second telecommunication point DIPS confirms the first MAC message "ATTRIBUTES_T._REQUEST" by sending the second MAC message "ATTRIBUTES_T._CONFIRM" to the first telecommunication point DIFS. Thereafter, the third subsystem channel C _{s is used} for information transmission at the C level and the second subsystem channel C _ε by transmitting the third MAC message "RELEASE" (cf. ETSI publication ETS 300175-3, October 1992, chapter 7.2 .5.3.13) resolved.

FIGURE 9 shows, starting from FIGURE 6, a fourth incentive-state diagram that represents the control sequence for the change from the second subsystem channel C _E to the first subsystem channel C _f , the preparation of the change being initiated by the first telecommunication interface DIFS becomes.

The second subsystem channel C _s is used for information transmission on the C level. In addition, the U- Level used. A transmission path with a transmission path number LCN (identifier) for using the first subsystem channel C _ε has not yet been set up. The second subsystem channel C _ε has a smaller transmission capacity than the first subsystem channel C _f .

The first telecommunication interface DIFS recognizes that the first subsystem channel Cf is necessary. However, since there is still no transmission path with the identifier LCN for the first subsystem channel Cf, the first telecommunications

Interface DIFS of the second telecommunications interface DIPS the first MAC message "ATTRIBUTES_T._REQUEST" (cf. ETSI publication ETS 300175-3, October 1992, chap. 7.2.5.3.8). With this message, it shares the second telecommunications Interface DIPS with the fact that a transmission path with the identifier LCN, for example the identifier LCNO, is required for the first subsystem channel C _£ .

The choice of the identifier LCN - in the present case the LCNO - as the identifier for the transmission path to be set up is not made arbitrarily, but specifically according to a predetermined selection criterion. In general terms, this criterion consists in that the identifier LCN is the identifier of the possible identifiers LCNO, LCN1, LCN2 which is not yet used for another transmission path, that is to say is free.

As an alternative to the selection criterion mentioned above, it is also possible to use special characteristics of the selection criterion for the assignment of the identifier. For example, As in the present case, the smallest free identifier of the identifiers LCNO, LCN1, LCN2 or the largest free identifier of the identifiers LCNO, LCN1, LCN2 are always used.

The second telecommunication interface DIPS, which according to the explanations in the description of FIG. 6 is preferably responsible for the establishment of a transmission path (cf. ETSI publication ETS 300175-3, October 1992, chap. 10.5.1.2 and 10.5.1.3), sends the DECT-specific first B-field message "BEARER_REQUEST" (cf. ETSI publication ETS 300175-3, October 1992, chapter 7.3.3.2) as a command (COMMAND) to the First telecommunications interface DIFS The first telecommunications interface DIFS then sends the DECT-specific second B-field message "BEARER_CONFIRM" after receiving the first B-field message (cf. ETSI publication ETS 300175-3, October 1992, chapter 7.3. 3.3) as a response (RESPONSE) to the second telecommunication interface DIPS. In this state, ie after receipt of the second B-field message by the second telecommunication interface DIPS, the further transmission path is established (cf. ETSI publication ETS 300175-3, October 1992, chap. 10.5.1.1 to 10.5 .1.3).

The first telecommunications interface DIFS then sends the first MAC message "ATTRIBUTES_T._REQUEST" (cf. ETSI publication ETS 300175-3, October 1992, chapter 7.2.5.3.8) to the second telecommunications interface DIPS.

The second telecommunications interface DIPS confirms the first MAC message "ATTRIBUTES_T._REQUEST" by sending the second MAC message "ATTRIBUTES_T._CONFIRM" to the first telecommunications interface DIFS. The first subsystem channel Cf is then used for information transmission at the C level.

FIGURE 10 shows, starting from FIGURE 6, a fifth incentive-state diagram that shows the control sequence for the change from the second subsystem channel C _s to the first subsystem channel

Cf represents, wherein the preparation of the switch is initiated by the second telecommunication interface DIPS.

The second subsystem channel C _s is used for information transmission at the C level. The U level is also used. A transmission route with a transmission route number LCN (identifier) for using the first subsystem nal Cf has not yet been set up. The second subsystem channel C _s has a smaller transmission capacity than the first subsystem channel C _f .

The second telecommunication interface DIFS recognizes that the first subsystem channel Cf is necessary. However, since there is still no transmission path with the identifier LCN, for example the identifier LCNO, for the first subsystem channel C _f , this is set up by it.

The choice of the identifier LCN - in the present case the LCNO - as an identifier for the transmission path to be set up is not made arbitrarily, but again specifically according to a predetermined selection criterion. This criterion is generally formulated in that the identifier LCN is the identifier of the possible identifiers LCNO, LCN1, LCN2 which is not yet used for another transmission path,

The second telecommunication interface DIPS sends the structure of the transmission path, which, according to the explanations given in the description of FIG. 6, is preferably responsible for the structure of a transmission path (cf. ETSI publication ETS 300175-3, October 1992, chapter 10.5 .1.2 and 10.5.1.3), the first telecommunications interface DIFS the DECT-specific first B-field message "BEARER_REQUEST" (cf. ETSI publication ETS 300175-3, October 1992, chap. 7.3.3.2) as a command (COMMAND) . The first telecommunication interface DIFS then sends the DECT-specific second B-field message "BEARER_CONFIRM" after receiving the first B-field message (cf. ETSI publication ETS 300175-3, October 1992, chap. 7.3.3.3) as a response (RESPONSE) to the second telecommunication interface

DIPS. In this state, ie after receipt of the second B-field message by the second telecommunication interface DIPS, the further transmission path is established (cf. ETSI publication ETS 300175-3, October 1992, chap. 10.5.1.1 to 10.5.1.3).

This is recognized by the first telecommunication interface DIFS, so that this is the first MAC message

"ATTRIBUTES_T._REQUEST" (cf. ETSI publication ETS 300175-3, October 1992, chap. 7.2.5.3.8) sends to the second telecommunication center DIPS.

The second telecommunications interface DIPS confirms the first MAC message "ATTRIBUTES_T._REQUEST" by sending the second MAC message "ATTRIBUTES_T._CONFIRM" to the first telecommunications interface DIFS. The first subsystem channel C _{f is then used} for the information transmission at the C level.

A second exemplary embodiment of the invention is explained with reference to FIGS. 11 to 15.

FIG. 11 shows, based on FIGS. 1 to 5, the basic structure of a transmitting part and receiving part for the first telecommunication interface DIFS and the second telecommunication interface DIPS, which is used for the analysis of the ISDN "layer 2" / "layer 3" messages or the amount of messages transmitted via this (cf. publication "Nachrich¬ tentechnik Elektronik, Berlin 41, T2: (1991) Issue 4, pages 138 to 143;") on the transmission line "ISDN network <—> ISDN subscriber (terminal endpoint TE) "of importance. Recognize / detect by the transmitting part and / or the receiving part For example, the first telecommunication interface DIFS and / or the second telecommunication interface DIPS knows the need to bring about a channel change (change from one subsystem channel to another subsystem channel). The result of the analysis forms the stimulus for the channel change. The structure of the transmitting part and receiving part shown in FIG. 11 can also be used for the first exemplary embodiment of the invention in connection with the stimulation of the channel change.

In the transmission part of the first telecommunication interface DIFS or the second telecommunication interface DIPS, the NWK layer (NetWorKlayer) transfers ISDN "layer 2" / "layer 3" information and DECT control information via a first embodiment formed as a memory in a known manner - Teεchlange WSD to the DLC layer (Data Link Control). A MAC / DLC control device STE of the transmitting part measures the full degree in the queue WSD and stimulates the MAC layer (Medium Access Control) and DLC layer therefrom. As long as the full degree remains below a threshold SD, the DLC layer stores the information (message) to be transmitted in a second queue WSS, likewise formed as a memory, from which it transmits the MAC layer on the C ₃ channel to the receiving point.

When the threshold SD is exceeded, the DLC layer stores the information in a third queue WSF, which is in turn formed as memory, from which it transmits the MAC layer to the receiving part on a C _f channel that is set up for this purpose . The C ₃ channel is used again when the first queue WSD and the third queue WSF are empty.

For the resulting channel change between the C _E channel and the C _f channel, it is assumed that the assignment of the C ₃ channel <--> C _f channel in the first telecommunication interface DIFS and the second telecommunication interface place DIPS using the DECT standard is known. Like the C ₃ channel, the C _f channel can of course also be used for transmissions in the opposite direction, provided it is already existent.

Function in detail

As long as the full degree of the first queue WSD is below the threshold SD, the DLC layer uses the DECT-A-field format (DECT standard) to feed the second queue WSS. After the threshold SD has been exceeded, the third queue WSF is fed in the DECT B field format. The switchover for transmission from the third queue WSF takes place after the establishment of the Cf channel, if the second queue WSS is empty or the C _£ channel is ready.

There are two options for the transition from A format to B format:

a) Waiting queue WSS only receives complete A-field DLC frames:

The switchover then always takes place at DLC frame boundaries. There are three criteria for the dimensioning of the DLC frames: frames as short as possible so that the delay in switching to transmit from the third queue WSF remains as short as possible, and on the other hand the DLC-PDU data overhang (data overhead; protocol data) increases if) the maxiamle DLC frame length is not used, - bridging the setup time for the C _f channel.

DLC procedures (Data Link Control) are used to control the switchover of the C _ε channel <--> C _f channel.

For example, the DECT standard procedures "Class B acknowledged suspension / Class B resumption" come in a modified form specifically for this application (cf. DECT standard ETS 300175-4, Oct. 1992, chap. 9.2.7) in question.

C, channel -> C _t channel according to FIGURE 12

If the first queue WSS is empty, ie the last I frame is acknowledged according to the HDLC protocol, the initiating telecommunication interface DIFS, DIPS (eg the second telecommunication interface DIPS) sends a command "SUSPEND" on the C _ε channel. If the If the remote station (the first telecommunication interface DIFS) itself has to send I-frames from the first queue WSS, it ends the earliest at the next frame boundary (remaining frames are transferred to the third queue WSF), the last acknowledgment awaits on the C _ε - Channel and then accepts the command "SUSPEND" (suspension) on the C _ε channel.

The second telecommunications interface DIPS then initiates the resumption of the connection (data link) by means of a “RESUME” command on the C _£ channel. The first telecommunications interface DIFS acknowledges this on the C _f channel. Then both telecommunications interfaces set DIFS, DIPS the transmission continues on the Cf channel.

C _f channel -> C. channel according to FIGURE 13

The downshift takes place when the first queue WSD and the third queue WSF are empty on both sides and the last I frame is acknowledged.

A distinction is made between two cases

The condition is first met at the telecommunications interface that caused the switchover (the second telecommunications interface DIPS). the second telecommunication interface DIPS sends the command "SUSPEND" on the C _£ channel. the first telecommunication interface DIFS rejects the "SUSPEND" command on the C _f channel and continues to send information on the C _f channel, the first telecommunication interface DIFS consequently also takes the initiative to switch to the C _ε - Channel and in turn initiates the "Suspension / Resumption" when the Cf channel is no longer required. In the meantime, the second telecommunication interface DIPS could spontaneously use the C _f channel again if required.

The condition for the telecommunication interface DIFS, DIPS, which previously caused or maintained the switchover to the C _f channel, will be met later.

This case ends the use of the C _f channel and switches back to the C _ε channel.

In this case, the answering telecommunication interface DIFS, DIPS accepts the "suspension" on the C _f channel. The suspending telecommunication interface DIFS, DIPS then initiates the "resumption" on the C _E channel.

b) switching within I-frames

This approach avoids the additional data overhead (overhead) for optimal DLC frames, but assumes that the switchover C _ε channel <--> C _£ channel for the DLC layer is complete and that the exact switchover point also for the receiver catcher is recognizable.

After the start of a frame in the second queue WSS, the DLC layer in the transmitting part specifies a frame length L, but must expect that it is necessary to switch to the third queue WSF within the frame and that the frame there must be closed in B-field format . In this case, it stores L and all that have already been transferred to the second queue WSS. NEN data and can form the frame conclusion (full octets, checksum) according to B-field rules.

An extension of the more standardized functions of the MAC layer can be used to control the switchover for the DLC layer without gaps. This extension affects the A field as follows (ε. ETS 300 175-3, 7.2.5, in particular 7.2.5.3 ff.).

- In the MAC message header, the code points that are still free are assigned the MAC command type “switchover C _ε channel / Cf channel”.

The rest of the A field essentially contains the following information under this command: - Reference of the MAC connections between which the C ₃ -channel / C _£ -channel switchover is to take place (the already defined ECN; Exchanged Connection Number is used) . Specific switching command C _ε channel -> C _£ channel / Cf channel -> C _ε channel. - Acknowledgment: switchover accepted / not accepted, confirmation of correct receipt of the command "acknowledgment". Blank field (use the waiting function if it cannot be acknowledged immediately).

The B field of the time slots with these MAC control information either carries user information (U level) if the C _ε channel is used or the signaling information itself or no information when the C ₃ channel is used.

The switching in the I-frame takes place according to a scheme similar to that outlined above in point "a)":

C. channel -> C _f channel according to FIG. 14

The initiating telecommunications interface DIFS, DIPS sends on the C ₃ channel after the MAC connection has been established the Cf channel instead of an I-frame segment, the switchover command C _ε channel -> C _£ channel. The opposite side acknowledges acceptance on the C _ε channel (there is no reason for rejection in this case). Then both telecommunication interfaces DIFS, DIPS continue the transmission on the C _£ channel.

C _£ channel -> C. channel according to FIGURE 15

If the telecommunication interface DIFS, DIPS initiating the C _f channel no longer needs this channel, it sends the switching command Cf channel -> C _ε channel on the C ^ channel. If the other side no longer needs this channel at this time (WSD, WSF empty), it acknowledges the acceptance of the downshift. Otherwise, it rejects the downshift and in turn takes over the initiative to restart the downshift when it no longer needs the C _£ channel. As long as the C _f channel is active, it can also be used by the opposite side.

annotation

The method can of course also be used at I-frame boundaries.

There are two options:

- MAC commands and acknowledgments are used at DLC frame boundaries, i.e. sent.

- MAC commands and acknowledgments are already displayed preventively in ongoing transmissions of DLC frames

However, the time of effectiveness is defined on DLC frame ends.

This results in the advantage of saving time because negotiations and possibly subsequent operations can already take place in parallel with a transmission that is still running. Other

The C _f channel can be set up according to DECT rules if required by both telecommunication interfaces DIFS, DIPS. Collisions should lead to a common channel.

In the event of a collision between assembly and dismantling, dismantling has priority.

The use of the C _f channel can also be stimulated by other criteria.

Claims

claims

1. Method for controlling the change of telecommunication channels of a telecommunication subsystem integrated in a telecommunication system as a local night transmission loop, in particular a DECT-specific RLL / WLL subsystem integrated in an ISDN system, with a) in the telecommunication system (I-ITS ) System information is transmitted, b) the telecommunication subsystem (DIIS) contains several subsystem channels (C _s , C _f ) for the transmission of subsystem information and the system information, c) the telecommunication subsystem (DIIS) contains two telecommunication control points (DIFS, DIPS) which are connected to each other at least via a subsystem channel (C _x ) of the subsystem channels (C _ε , C _f ), d) the telecommunication subsystem (DIIS) via the two telecommunication interfaces (DIFS, DIPS) into the telecommunication system (ISDN) is involved, e) on the subsystem channel (C _x ) of the subsystem channels (C _s , C _f ) the information is transmitted, characterized in that f) a switchover command (SWITCHING_REQUEST,

ATTRIBUTE_REQUEST, SUSPEND) is transmitted, with which the two telecommunications interfaces (DIFS, DIPS) of the other telecommunications interface (DIFS, DIPS) signals that the information is transmitted on another subsystem channel (C _y ) of the subsystem channels (C _s , C _f ) g) a switchover response (SWITCHING_CONFIRM,

ATTRIBUTE_CONFIRM, RESUME) is transmitted from the telecommunication interface receiving the switch command (DIFS, DIPS) to the telecommunication interface sending the switch command (DIFS, DIPS).

2nd Method according to claim 1, characterized in that the transmission of the switchover command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) is stimulated by the result of an analysis of the information to be transmitted in the telecommunications subsystem (DIIS) by at least one of the two telecommunication interfaces (DIFS, DIPS).

3. The method according to claim 2, characterized in that the result of the analysis is that no information has been transmitted between the telecommunication interfaces (DIFS, DIPS) on the subsystem channel (C _x ) for a predetermined period of time.

4. The method according to claim 1, characterized in that the switchover command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) is retransmitted if the switchover response (SWITCHING_CONFIRM, ATTRIBUTE_CONFIRM) is not transmitted after a predetermined period of time.

5. The method according to claim 4, characterized in that the changeover command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) is repeated for a predetermined number of times when the changeover response (SWITCHING_CONFIRM, ATTRIBUTE_CONFIRM) is not transmitted before the control of the channel change is interrupted for an undetermined number.

6. The method according to one of claims 1 to 3, characterized in that the switchover response (SWITCHING_CONFIRM, ATTRIBUTE_CONFIRM) is a switchover confirmation with which the telecommunications interface receiving the switchover command (DIFS, DIPS) and the switchover command send the switchover command. DIPS) signals that the information is transmitted on the other subsystem channel (C _y ).

7. The method according to any one of claims 1 to 6, characterized in that the transmission of the information is interrupted before, with or after the transmission of the switchover command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) and that with or after the transmission of the switchover response (SWITCHING_CONFIRM, ATTRIBUTE_CONFIRM) Transmission of the information is resumed.

8. The method according to claim 7, characterized in that the transmission of the information is interrupted immediately after the transfer of the switch command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) and that essentially immediately after the transfer of the switch command

(SWITCHING_REQUEST, ATTRIBUTE_REQUEST) the switchover response (SWITCHINGJCONFIRM, ATTRIBUTE_CONFIRM) is transmitted.

9. Method according to Claim 7, characterized in that immediately after the transfer of the switchover command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) the transmission of the information is interrupted by the telecommunication interface (DIFS, DIPS) sending the switchover command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST), that essentially immediately after the transfer of the switchover command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST), the transmission of the information by the telecommunication interface (DIFS, DIPS) receiving the switchover command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) is interrupted when a DIFI interface (DIFS) interface (DIF) is used by this telecommunication interface the self-contained information package has finally been transmitted and that the switchover response (SWITCHING_CONFIRM, ATTRIBUTE_CONFIRM) is transmitted essentially immediately after the transmission of the information package.

10. The method according to claim 7, characterized gekennzeich¬ net that immediately after the transmission of the Umschaltkommandoε (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) the transmission of information by the Umschaltkommando

(SWITCHING_REQUEST, ATTRIBUTE_REQUEST) terminating telecommunications interface (DIFS, DIPS) is interrupted, that essentially immediately after the transfer of the changeover command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) the information is transmitted by the changeover command

(SWITCHING_REQUEST, ATTRIBUTE_REQUEST) receiving telecommunication interface (DIFS, DIPS) is interrupted after a predetermined period of time to confirm information already received and that the changeover response is essentially immediate after the confirmation has been transmitted

(SWITCHING_CONFIRM, ATTRIBUTE_CONFIRM) is transmitted.

11. The method according to any one of claims 1 to 10, characterized in that predetermined subsystem-specific parameters are reset after the transfer of the changeover response and before the transmission of the system information on the other subsystem channel (C _y ).

12. The method according to any one of claims 1 to 11, characterized in that a test message is sent on the other subsystem channel (C ,,) after a channel change with a request for confirmation.

13. The method according to claim 12, characterized in that the test message is a RECEIVE_READY message that is sent as a command (COMMAND) and that the confirmation is a RECEIVE_READY message that is sent as the response (RESPONSE).

14. The method according to claim 7, 8 or 10, characterized ge ¬ indicates that em is transmitted by the immediate interruption incompletely transmitted or unanswered information packet of the information to be transmitted on the other subsystem channel (C _y ) after a channel change.

15. The method according to any one of claims 1 to 14, characterized in that the information is transmitted according to a predetermined transmission principle with a predetermined transmission sequence (k = 3) and that the information is transmitted on the other subsystem channel (C _y ) after a channel change a possible transmission sequence (k = 1) are transmitted.

16. The method according to claim 15, characterized in that the transmission principle with the predetermined transmission sequence daε HDLC protocol for the transmission of HDLC frames.

17. The method according to any one of claims 1 to 16, characterized in that

System messages with useful information and / or the system information and / or the subsystem information between the telecommunication interfaces (DIFS, DIPS) of the telecommunication subsystem (WLL / RLL) are transmitted on transmission paths with different identifiers (LCNx, LCNy, LCNz).

18. The method according to claim 17, characterized gekennzeich¬ net that a first transmission path, to which a first subsystem channel (C _£ ) is assigned, is assigned a first identifier which is not occupied by other transmission paths.

19. The method according to claim 18, characterized in that the first identifier is the respective smallest assignable identifier of the identifiers characterizing the transmission paths (LCNx, LCNy, LCNz).

20. The method according to claim 18, characterized in that the first identifier reads the largest assignable identifier from the identifiers characterizing the transmission paths (LCNx, LCNy, LCNz).

21. The method according to any one of claims 1 to 20, characterized in that the subsystem channel (C _x ) and the other subsystem channel (C _y ) have different transmission capacities.

22. The method according to any one of claims 1 to 20, characterized in that the subsystem channel (C _x ) and the other subsystem channel (C _y ) have the same transmission capacities.

23. The method according to emem of claims 1 to 22, characterized in that the switchover command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) is transmitted by a first telecommunications interface (DIFS).

24. The method according to any one of claims 18 to 20 and according to claims 21 and 23, characterized in that the first subsystem channel (C _£ ) with respect to the transmission capacity is larger than a second subsystem channel (C _ε ), that the first subsystem channel (C _t ) the first transmission path with the first identifier and the second subsystem channel (C _ε ) is assigned to a second transmission path with a second identifier and that the first subsystem channel (Cf) is switched to the second subsystem channel (C _s ) by a) a changeover command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) is transmitted from the first telecommunications interface (DIFS) to a second telecommunications interface (DIPS) with which the first telecommunications interface (DIFS) signals the second telecommunications interface (DIFS) Information is to be transmitted on the second subsystem channel (C _s ), b) a switch response (SWITCHING_CONFIRM, ATTRIBUTE_CONFIRM) is transmitted from the second telecommunication interface (DIPS) to the first telecommunication interface (DIFS).

25. The method according to any one of claims 18 to 20 ε as well as according to claims 22 and 23, characterized in that a second subsystem channel (C _s ) with respect to the transmission capacity is equal to a third subsystem channel (C _s ), that the second subsystem channel (C _ε ) a second transmission path with a second identifier and the third subsystem channel (C _ε ) is assigned to a third transmission path with a third identifier and that the second subsystem channel (C _s ) is switched to the third subsystem channel (C _ε ) by a) a toggle command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) is transmitted from the first telecommunications interface (DIFS) to the second telecommunications interface (DIPS), with which the first telecommunications interface (DIFS) signals the second telecommunications interface (DIPS) that the information on the third subsystem channel (C _s ) are to be transmitted, b) a response (SWIT CHING_CONFIRM, ATTRIBUTE_CONFIRM) is transmitted from the second telecommunications interface (DIPS) to the first telecommunications interface (DIFS).

26. Method according to one of claims 18 to 20 and according to claims 21 and 23, characterized in that the first subsystem channel (C _t ) is greater in transmission capacity than a second subsystem channel (C _ε ), that the second subsystem channel (C _£ ) is assigned to a second transmission path with a second identifier, that the first transmission path is associated with the first Identifier for the first subsystem channel (C _£ ) is built up and that the second subsystem channel (C _ε ) is switched to the first subsystem channel (C _£ ) by a) a switchover command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) from the first telecommunications interfaces (DIFS) to the second telecommunications interface (DIPS) is transmitted, with which the first telecommunications interface (DIFS) signals the second telecommunications interface (DIPS) that the information is to be transmitted on the first subsystem channel (C _£ ), b) a switchover response (SWITCHING_CONFIRM, ATTRIBUTE_CONFIRM) from the second telecommunications interface e (DIPS) is transmitted to the first telecommunications interface (DIFS).

27. The method according to claim 26, characterized in that the establishment of the first transmission path with the first identifier for the first subsystem channel (C _£ ) is initiated by the first telecommunications interface (DIFS).

28. The method according to claim 26, characterized in that the establishment of the first transmission path with the first identifier for the first subsystem channel (C _£ ) is initiated by the second telecommunications interface (DIPS).

29. The method according to any one of claims 1 to 3 or claims 1 and 7, characterized in that the switching command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) and / or the switching response (SWITCHING_CONFIRM, ATTRIBUTE_CONFIRM) is acknowledged by the respective switching command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) or the switching response (SWITCHING_CONFIRM, ATTRIBUTE_CONFIRM) receiving telecommunications interface {).

30. The method according to claim 29, characterized in that the switch command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) and / or the switch response (SWITCHING_CONFIRM, ATTRIBUTE_CONFIRM) is acknowledged in a negative or accepting manner.

31. The method according to claim 30, characterized in that, in the event of the rejection of the switching command

(SWITCHING_REQUEST, ATTRIBUTE_REQUEST) or the Umschaltant¬ word (SWITCHING_CONFIRM, ATTRIBUTE_CONFIRM) is the respective rejection signaling telecommunications interface (DIFS, DIPS) deε the channel change with the transmission switchover command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) is ansto¬ SEN.

32. The method according to any one of claims 1 to 3 and according to claim 7 and 30, characterized in that in the event of acceptance of the switching command

(SWITCHING_REQUEST, ATTRIBUTE_REQUEST) and the switchover response (SWITCHING_CONFIRM, ATTRIBUTE_CONFIRM) starts the transmission of the information after the resumption of the transmission at the point where the transmission has been interrupted.

33. The method according to any one of claims 1 to 3, claims 1 and 7 or one of claims 29 to 32, characterized ge ¬ indicates that the switching command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) from a first telecommunications interface (DIFS) or a second telecommunication interface (DIPS) is transmitted.

34. The method according to one of claims 1 to 3, claims 1 and 7 or one of claims 29 to 33, characterized in that the switch command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) and the switch response (SWITCHING_CONFIRM, ATTRIBUTE_CONFIRM) in a first message transmission (DLC layer) of a message transmission structure of the telecommunication interface (DIFS, DIPS) divided into message transmission layers, in which essentially the subsystem information is transmitted.

35. Method according to one of claims 1 to 3, claims 1 and 7 or one of claims 29 to 33, characterized by the fact that the switching command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) and the switching response (SWITCHING_CONFIRM,

ATTRIBUTE_CONFIRM) are transmitted in a second message transmission layer (MAC layer), which relates to a message transmission structure of the telecommunications interface (DIFS, DIPS) divided into message transmission layers of a first message transmission layer (DLC) which is essentially provided for the transmission of the subsystem information. Layer) is subordinate and that the switchover command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) and the switch response (SWITCHING_CONFIRM, ATTRIBUTE_CONFIRM) are transmitted in such a way that the data structure of the first message transmission layer (DLC layer) remains unaffected.

36. Method according to one of claims 1 to 35, characterized in that the telecommunication system (ISDN) is an ISDN system.

37. Method according to claim 36, characterized in that the system information is transmitted on the D channel.

38. The method according to any one of claims 1 to 37, characterized in that the telecommunication part system (DIIS) contains a DECT / GAP system (DGS).

39. Method according to one of claims 1 to 37, characterized in that the telecommunication subsystem (DIIS) contains a GSM system.

40. The method according to any one of claims 1 to 37, characterized in that daε Telekommunikationεteilεyεtem (DIIS) contains a PHS system, a WACS system or a PACS system.

41. The method according to any one of claims 1 to 37, characterized in that daε Telekommunikationεteilεyεtem (DIIS) contains an "IS-54" system or a PDC system.

42. The method according to any one of claims 1 to 37, characterized in that the telecommunication subsystem (DIIS) contains a CDMA system, a TDMA system, an FDMA system or a - with regard to said transmission standards - hybrid system.

43. The method according to claim 38, characterized in that the first telecommunication interface (DIFS) is a DECT INTERMEDIATE FIXED SYSTEM (DIFS) and the second telecommunication interface (DIPS) is a DECT INTERMEDIATE PORTABLE SYSTEM (DIPS).

44. The method according to claim 38, characterized in that the partial system channel (C _x ) or the other partial system channel (C _y ) or the first partial system channel (C _f ) is the C _f channel of the DECT / GAP system (DGS). is.

45. The method according to claim 38, characterized in that the subsystem channel (C _x ) or the other subsystem channel (C _y ) or the second subsystem channel (C _ε ) and the third subsystem channel (C _ε ) of the C ₃ - Channel of the DECT / GAP system (DGS) is or is.

46. Method according to one of claims 1 to 29 and according to claim 38, characterized in that the switching command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) is the ATTRIBUTE_REQUEST information element of the DECT standard.

47. Method according to one of claims 1 to 29 or claim 46 and according to claim 38, characterized in that the switchover response (SWITCHING_CONFIRM, ATTRIBUTE_CONFIRM) is the ATTRIBUTE_CONFIRM information element of the DECT standard.

48. Method according to one of claims 1 to 3, claims 1 and 7 or one of claims 29 to 35 and according to claim 38, characterized in that the switch command (SWITCHING_REQUEST, ATTRIBUTE_REQUEST) is the SUSPEND information element de: DECT standards.

49. The method according to one of claims 1 to 3, claims 1 and 7, one of claims 29 to 35 or claim 48 and according to claim 38, characterized in that the switchover response (SWITCHING_CONFIRM, ATTRIBUTE_CONFIRM) is the RESUME information element of the DECT standard .

50. Method according to claim 34, characterized in that the first message transmission layer is the DLC layer (Data Link Control) of the DECT standard.

51. The method according to claim 35, characterized in that the second message transmission layer is the MAC layer (Medium Access Control) of the DECT standard.