FI105752B - Data transmission in a communication system - Google Patents

Description

w 1 105752

Data transmission in a communication system

The invention relates to data transmission in telecommunication systems.

In mobile communication systems, the available data transmission capacity of the radio interface 5 is distributed among a plurality of users on a multiple access basis. The most common multiple access principles are Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA) and Frequency Division Multiple Access (FDMA). In TDMA systems, communication on a radio path is time-sharing, occurring in successive TDMA frames, each comprising a plurality of time slots. In the KUS-10 slots, a short information packet is transmitted in the form of a finite duration radio frequency burst consisting of a plurality of modulated bits. The slots are mainly used to transfer control channels and traffic channels. Voice and data are transmitted over traffic channels. The control channels carry out signaling between the base station and the mobile stations. An example of a TDMA radio-15 system is the Global System for Mobile Communications GSM. In a CDMA system, a traffic channel is defined by a unique spreading code assigned to a mobile station, while in a FDMA system, a traffic channel is defined by a radio channel.

The maximum data transfer rate per traffic channel is limited by the relatively low bandwidth available and the channel coding and error coding used in the transmission. For example, in a GSM system (Global System for Mobile Communications), a traffic channel using a single time slot, the user data rate was initially limited to 9.6 kbit / s, with a radio interface rate of 12 kbit / s.

'25 This was found to be inadequate for many new telecommunications services such as fax, video transmission, etc. As a result, high-speed data transmission services based on so-called data transmission services are being introduced into new mobile communication systems. monika-navatekniikkaan. In multichannel technology, the mobile station is provided with a higher bit rate and bandwidth in the form of multiple parallel basic traffic channels (e.g., 30 multiple time slots). For example, the GSM mobile communication system defines a High Speed Circuit Switch Data (HSCSD) service as ETSI (European Telecommunications Standards Institute) recommendations GSM 01.34, GSM 02.34 and GSM 03.34. In the HSCSD concept, the high-speed data signal is divided into separate data streams, which are then transmitted over N Alika-35 hubs (N traffic channel slots) at the radio interface and N subchannels respectively between the base station and the mobile switching center (transcoder).

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Once the data streams are divided, they are transported in the subchannels as if they were independent when they are reconnected at the receiving end. However, logically, these N sub-traffic channels belong to the same HSCSD connection, i.e., form one HSCSD traffic channel. The capacity of the HSCSD traffic channel is thus up to eight times the capacity of the basic traffic channel, leading to a significant improvement in the data transfer rate. The GSM-HSCSD is capable of supporting 96 kbit / s (8 x 12 kbit / s) radio interface speeds and up to 64 kbit / s and 76.8 kbit / s (8 x 9.6 kbit / s) radio speeds.

Digital mobile communication systems, especially in TDMA-based systems such as GSM, use radio system timing to synchronize data transmission over the air interface. For example, in GSM, the basic timing unit is 20 milliseconds (ms). In a transparent circuit-switched data call, this 20 ms unit corresponds to four V.110 frames (in the case of TCH / F9.6 15 or TCH / F4.8 or TCH / F2.4 channel coding) or one E-TRAU frame (in the case where is TCH / F14.4 channel coding). In a non-transparent call, this 20 ms unit corresponds to one radio link protocol (RLP) frame (in the case of TCH / F9.6 or TCH / F4.8 channel coding) or one half of the RLP frame (in the case of TCH / F14.4 channel coding). In the aforementioned case, the halves of the RLP frame are separated by an indication bit.

The above TCH / F14.4 channel coding was later introduced into the GSM system when higher data rates were required. In non-transparent calls, the TCH / F14.4 channel coding required a new version of the RLP protocol * 25 because the larger bit rate of the said basic timing unit 20 msec did not match the RLP frame length or its multiple. The TCH / F14.4 also produced a fairly coarse re-mapping procedure which allows swapping between TCH / F14.4 and TCH / F9.6 channel codings during a data call. The reason for this swapping function is, for example, optimizing 30 connections after a change in radio quality or a handover between two cells, one supporting TCH / F14.4 channel coding. For a transparent 14.4 kbit / s call, the new TCH / F14.4 channel coding provided a very well optimized rate match: 14.5 kbit / s radio boundary surface rate with 14.4 kbit / s of user data, adapted to a new bitrate of 20ms basic run-35 .

3 105752

If new channel coding is introduced into GSM, the same problem as with TCFH / F14.4 is encountered again: Each channel coding has a different number of bits in one basic timing unit of 20 ms. Some channel encodings may produce bit counts that are compatible with current 5 times frame rate matching frames or RLP frame multiples, other channel codings may produce bit numbers that require new RLP versions or new rate matching methods, while some channel codings may produce every bit of support used, only in a very inefficient way, ie with a significant overhead.

In addition, the ETSI EDGE (Enhanced Data Rates for GSM Evolution) project is developing a new modulation scheme that provides a higher data rate per slot than the current GMSK modulation, while maintaining a 200 kHz channel spacing and TDMA frame structure. This allows the existing HSCSD data services to be supported with a smaller number of time slots. In addition, the new modulation enables the production of new data services having up to 64 kbit / s data rate per time slot or more than 64 kbit / s (n * 64 kbit / s) in a multi-time slot constellation. The radio interface rate is either 28.8 kbits or 38.4 kbit / s. The new modulation method also produces new channel codings that encounter the problems described above.

20 Similar problems are encountered in other digital mobile communication systems and telecommunication systems in general.

There is now a need for a general method for mapping fixed length transmission frames to a timing unit (block) of any number of bits in a transport channel, i.e., the same transmission frames 25 may be transmitted through the system by different channel encodings to avoid new rate adaptations, efficiency (minimizing overhead).

It is an object of the invention to provide a method and system in which the problems described above are eliminated and the objects are achieved.

This is achieved by the method of claim 1 and the mobile communication system of claim .12.

In the invention, an information unit is transmitted over a transmission link, such as a radio interface, asynchronously in a basic 35 timing units of a transmission link (such as a radio interface), referred to herein as radio frames. The information units are located on two or more consecutive 105752 4 radio frames such that each radio frame contains at least one complete information unit and a portion of the information unit which is split into two successive radio frames. Thus, radio frames can be considered to contain asynchronous information units. One or more bits in the radio frame are provided for phase indication, by which the receiver is synchronized to asynchronous information units within the radio frames. The phase indication is modulo N, which defines the sequence of N consecutive radio frames and indicates, for each radio frame, which of the N possible radio frames in the frame sequence is that frame. The transmitting unit compresses the information units into radio-10 frames and provides the radio frames with the aforementioned phase indication. The last radio frame of the frame frame is packed with as many complete information units as possible (at least one) and the rest of the last radio frame is filled with filler bits if necessary. This is generally necessary when the number of bits required by the information units packaged in the frame sequence and the said phase indication is less than the total number of information bits in the frame sequence. This is typically the case in preferred embodiments of the invention, i.e., when the information field length of the radio frame is not the length of the information unit to be transmitted or its multiple. The padding bits may also be inserted into the frame sequence in ways other than the end of the last radio frame 20. The receiving unit detects the phasing between the radio frames and the asynchronous information units in the radio frames by synchronizing with said phase indication. In other words, the receiving unit identifies from the phase indication where the start of the frame sequence is and the start of each whole information unit in the radio frame and extracts the information units from the radio frames for further processing. Any filler bits are rejected by the receiving unit.

The information unit may be any protocol unit or frame or information element to be transmitted over the radio interface. It may be, for example, a transmission frame used for data transmission between a network element of a radio access network, such as a base station and a network adapter, such as A-TRAU or E-TRAU frames in a GSM system. The information unit may also be a protocol data unit of the upper protocol. Such is the protocol data unit of the link protocol set up between the mobile station and the Network Adapter, such as the Radio Link Protocol (RLP) frame in the GSM system. By means of the invention, the same fixed-length information unit can be fitted to a radio frame of any number of bits, i.e., the same information units can be transmitted through the radio interface of the radio system by different channel codings. All that needs to be done is to select the appropriate value for the N modulo N sequence and the appropriate number of padding bits for each different radio frame type or channel coding. In other words, the radio system may have

»'...... T

5 own modulo N sequences for different data rates and channel coding.

Thanks to the invention, the same information unit can be used in a radio system with different channel coding. The present invention may be applied, for example, to transmit existing RLP frames and transparent rate adaptation frames through new EDGE channel coding, thus avoiding the need to define new RLP versions, rate adaptation methods, and resampling procedures.

The invention optimizes the efficiency of channel coding because it causes very little overhead in the system. Typically, the phase indication occupies one bit or only a few bits of the radio frame. The phase indication may be, for example, a virtual noise (PN) code spread over N radio frames. This is very effective because only one bit in each radio frame is required. For example, in the case of a 31-bit PN code, the modular sequence of radio frames has a maximum of 31 frames and the receiver needs to receive five radio frames to synchronize to the sequence, i.e. locked to the correct phase so that the receiver knows what 31 frames are and -sessä. If enough bits are available in the radio frame for phase indication, the phase indication may also be, for example, a sequence number (0, 1, 2, 3 ...). In this case, the receiver only needs to receive one radio frame in order to become synchronized with the frame sequence. Also, if sufficient Hifi is available, the phase indication may be coded to protect against transmission errors that may be caused by transmission over the radio path.

The invention will now be described in more detail in connection with preferred embodiments, with reference to the accompanying drawings, in which: Figures 1A and 1B show a protocol structure for transparent and non-transparent traffic channels TCH / F4,8 and TCH / F9.6 in the GSM system,

Figure 2 illustrates the Abis interface protocols for the traffic channel TCH / F14.4 Figure 3 illustrates the channel configuration required by the EDGE traffic channel at 38.4 kbit / s in GSM; 105752 6

Figure 4 shows a Modulo N radio frame sequence according to the invention,

Figure 5A illustrates downlink ETRAU frames,

Figures 5B and 6A illustrate a radio frame-5 sequence according to the invention for a 38.4 kbit / s EDGE traffic channel,

FIG. 6B illustrates an information unit queue separated by a mobile station from received radio frames.

The present invention is applicable to all digital communication systems, and in particular to wireless communication systems such as cellular systems, WLL (Wireless Local Loop) and RLL (Radio Local Loop) networks, satellite based mobile communication systems, etc., for adding a new high speed traffic link to a radio interface. rate adaptations.

As used herein, the term mobile communication system (or network) refers generally to all 15 wireless communication systems. There are a number of multi-access modulation technologies to facilitate communication involving a large number of mobile users. These techniques include time division multiple access (TDMA), code division multiple access (CDMA), and frequency division multiple access (FDMA). The physical concept of a traffic channel varies in different multi-access methods, being primarily defined by time slot in TDMA systems, spreading code in CDMA systems, radio channel in FDMA systems, combinations thereof, etc. The basic idea of the present invention is independent of the type of traffic channel used. multiple access method.

The primary field of application of the invention is to adjust the EDGE radio interface li-: 25 or to make similar modifications to other GSM-based systems, such as DCS1800 (Digital Communication System), and the US Digital Cellular System PCS (Personal Communication System). based WLL systems. The invention will be described below using as an example a GSM mobile communication system. The structure and operation of the GSM system are well known to those skilled in the art and are defined by the European Telecommunications Standards (ETSI)

Institute) in GSM specifications. Reference is also made to the book "GSM-System for

Mobile Communication, "M. Mouly and M. Pautet, Palaiseau, France, 1992; ISBN: 2-9507190-0-7.

35 The basic structure of the GSM system consists of two parts: support

station system BSS and network subsystem (NSS). BSS and mobile stations MS

105752 communicate via radio. In the base station system BSS, each cell is served by the base station BTS. A plurality of base stations are connected to a base station controller BSC whose function is to control the radio frequencies and channels used by the BTS. The BSCs are connected to the mobile services switching center MSC. In addition, there are at least two databases, the home location register HLR and the visitor location register VLR.

The mobile communication system typically includes adapter functions for adapting the internal data connection of the mobile network to the protocols used by terminals and other communication networks. Typically, the adapter functions are a terminal adapter TAF (Terminal Adaptation Function) at the interface between the mobile station and a data terminal connected thereto, and a Network Adapter IWF (Interworking Function) at the interface between the mobile network and another telecommunication network. Usually, the mobile switching center has several types of adapter boot pools to support various data services and protocols, e.g. Between the TAF and the Network Adapter IWF in the mobile network. The TAF adapts the data terminal DTE connected to the mobile station MS to said GSM data connection which is established over a physical connection using one or more 20 traffic channels. The IWF connects the GSM data connection to another network, such as ISDN or another GSM network, or the public switched telephone network PSTN.

As explained previously, modern mobile communication systems support various telecommunication and network services. Network services are generally divided into *: 25 features, such as asynchronous network services and synchronous network services. Within each such group is a set of network services, such as the Transparent Service (T) and the Non-Transparent Service (NT). In Transparent, the data to be transferred in the service is unstructured and the transmission errors are corrected only by channel coding. The data to be transmitted in the non-transparent service is structured into Protocol Data Units (PDUs) and transmission errors are corrected (in addition to channel coding) by automatic retransmission protocols.

Figure 1A illustrates an example of protocols and functions required for transparent network services in an IWF (either an MSC or a WLL-specific network element). The transparent circuit switched connection between the terminal adapter TAF and the network adapter 35 IWF on a GSM traffic channel comprises a plurality of protocol layers common to all of these services. These 105752 8 include various rate adaptation functions RA, such as between the TAF of the RA1 'terminal adapter and the CCU (Channel Codec Unit) in the base station system BSS, between the RA1 CCU and the Network Adapter IWF, the RAA CCU and the transceiver station separately. Between the TRAU and the RA2 transcoder unit TRAU and the IWF Network Adapter. The acceleration adaptation functions RA are defined in GSM Recommendations 04.21 and 08.20. The communication between the CCU and the transcoder unit TRAU is defined in GSM Recommendation 08.60. In addition, the RAT rate matched information at the radio interface is channel coded as defined in GSM Recommendation 5.03, as illustrated by the blocks FEC in the mobile station MS and the CCU. In addition, IWF and TAF have higher level protocols that are service specific. In the asynchronous transparent network service of Figure 1A, the IWF requires an asynchronous-synchronous conversion RA0 and a modem or rate adapter towards the fixed network. The transparent signal 15 passes through a traffic channel between the terminal interface and the PSTN / ISDN. The transparent synchronous configuration is otherwise similar, but does not have a rate match RA0.

Referring to Figure 1B, in an asynchronous non-transparent network service, IWF and MS comprise, instead of RA0, L2R (Layer 2 Relay) and RLP (Radio 20 Link Protocol) protocols. L2R functionality for non-transparent character-oriented protocols is defined e.g. GSM Recommendation 07.02. The RLP protocol is defined in GSM Recommendation 04.22. The RLP is a frame-structured, balanced (HDLC-type) data transmission protocol in which error correction is based on receiving the retransmission of corrupted frames at the request of the part-25 side. The interface between the IWF and, for example, the MODEM audio modem is in accordance with CCITT V.24 and is indicated in FIG. 1B by the symbol L2.

This non-transparent configuration is also used to access the Internet.

Figures 1A and 1B relate to a network configuration in which a transcoder and part of the rate adaptations are located outside the base station BTS in a so-called remote transcoder TRAU. The transcoder is then considered to be functionally part of the BSC. Physically, the TRAU may be located in either the BSC or the MSC. The interface between the transcoder unit TRAU and the base station BTS is called the Abis interface. The Abis interface has 16 kbit / s traffic channels, which can be transferred four in one standard 64 kbit / s channel. The information is transmitted between the channel codec unit CCU and the transcoder unit TRAU in fixed length frames called TRAU frames. These frames carry both speech / data and control signals associated with the transcoder TRAU. In the case of 4.8 kbit / s (TCH / F4.8) and 9.6 kbit / s (TCH / F9.6) channel coding, when adapting the data to TRAU frames, a rate adaptation function of 5 RA1 / RAA is required in addition to other rate adaptations. At channel encoding of 14.4 kbit / s (TCH / F14.4), a slightly different rate adaptation function RA17 RAA 'is required, as illustrated in FIG. RA17RAA 'converts radio frames (blocks) into E-TRAU format and vice versa. The RAA'converts an E-TRAU frame into an A-TRAU frame and vice versa. Since the TCH / F14.4 channel-10 spatial coding rate match is probably the best alternative for traffic channels in the EDGE radio interface as well, the preferred embodiment of the invention will be described in terms of its implementation. However, it should be noted that the invention can also be implemented by other rate adaptations such as RA1 / RAA.

In the HSCSD concept of the GSM system, the high-speed data signal 15 is divided into separate data streams, which are then transmitted over N subchannels (N traffic channel slots) at the radio interface and through N transmission channels (16kbit / s) between the BTS-IWF. Once the data streams are shared, they are transported in the subchannels as if they were independent until they are combined again in IWF or MS. However, logically, these N sub-traffic channels belong to the same 20 HSCSD connections, i.e. form one HSCSD traffic channel. According to GSM recommendations, data stream splitting and combining is performed in a modified RAO or RLP, which is thus common to all subchannels. Below this common RA0 or RLP, each subchannel separately has the same protocol stack RA1 '-FEC-FEC-RA1' -RAA-RAA-RA2-RA2-RA1 or RAT- '! 25 FEC-FEC-RAT-RAA'-RAA'-RA2-RA2-RA1 shown in Figures 1A and 1B

for one traffic channel, between MS / TAF and MSC / IWF. In transparent data transmission between TAF-IWF traffic channels are numbered to maintain the order of the data. In addition, within the traffic track, overframing is used to increase tolerance for transmission delay differences between traffic channels. Channel and frame numbering are carried as inband signaling.

W · __ _

If an attempt is made to support the EDGE radio interface rate of 38.4 kbit / s with current channel structures and TCH / F14.4 rate adaptations between the BTS-IWF, the configuration of FIG. The 38.4 kbit / s EDGE channel requires three parallel 14.4 kbit / s channels between MS and MSC / IWF. With 35 38.4 kbit / s EDGE channels, the total transmission rates at the radio interface and the network interface are not the same. In addition, the radio interface must have a new 10 105752 channel coding. This results in the problems described above with respect to rate adaptations and RLP protocols, and the efficiency of channel coding.

The following is an analysis by the inventor of some applications of the 38.4 kbit / s user speed that could be alternatives to the present inventor and the problems involved.

If TCH / F9.6 speed matching with V.110 frames were used, the radio interface rate would be 48 kbit / s due to the V.110 overhead. This would imply poor channel coding since the selected EDGE modulation mode has a gross bit rate of 69.2 kbit / s. The radio interface rate should be as close as possible to 38.4 kbit / s to obtain better channel coding.

The use of a more efficient A-TRAU or E-TRAU rate match defined for TCH / F14.4 channel coding (at a radio interface rate of 14.5 kbit / s) would support multiple user data rates of 14.4 kbit / s. Here, a channel coding which would carry 3 * 14.5 15 kbit / s, or 43.5 kbit / s, corresponding to 43.2 kbit / s user data rate could be defined. This would still not be optimized for channel coding. Obtaining an accurate user data rate of 38.4 kbit / s (transparent) would require padding in the radio frame in this approach.

A third way would be to determine a new rate adaptation and a new RLP version suitable for optimized channel coding (e.g., 20 39 kbit / s at radio interface rate) with new re-mapping operations. This would require a great deal of specification and implementation work. This is also contrary to the goal of EDGE standardization to use existing protocols with minimal changes.

These problems can be avoided by the present invention, the basic principle of which is illustrated in Figure 4.

In the invention, the radio frames are provided with a phase indication P 1, P 1, which defines the sequence of the N radio frames. In other words, the phase indication PV..PN in each frame indicates which of the N possible frames in the frame sequence is that frame. The transmitting unit compresses the information units 30.,.,. Ιο into radio frames and provides the radio frames with the aforementioned phase indication of P. Typically, the information unit length is smaller than the information frame length of the radio frame, so the number of information units Q is greater than the number N of radio frames. Thus, each radio frame includes at least one whole information unit I (such as information units I12, I2, I4, I6 and IQ1) and a part of an information unit that is split into two consecutive radio frames (such as I51 and I52, which are split into one, 105752 11 total information units 15 to two radio frames). The last radio frame N of the frame sequence is packed with as many complete information units as possible, and the rest of the last radio frame is filled with fill bits FILL if necessary. The module N radio frame sec-5 forms a kind of superframe with phase indication P1-PN as synchronization information.

In the following, a possible embodiment of a 38.4 kbit / s user rate for following the principles of the present invention will be described with reference to Figures 5A, 5B, 6A and 6B. The new functionality provided by the invention is located, for example, in blocks RA1 'and RA17RAA' in the mobile station MS and the base station BTS in Figures 1A, 1B and 2.

As explained above with reference to Fig. 3, a user rate of 38.4 kbit / s can be carried in TCH / F14.4 channel coding in defined A-TRAU and E-TRAU frames between the Network Adapter MSC / IWF and the Base Station BTS using three 16 kbit / s Abis interface. s traffic channels, each with 14.4 kbit / s rate matching. To match the speeds of the radio interface and the transmission link, every ninth A-TRAU and E-TRAU frame is a dummy frame. BTS and IWF add dummy frames to the broadcast and discard them at the reception. _____ 20 Figure 5A illustrates groups of nine E-TRAU frames, eight of which have information content 1, ... 1, and one of which is a blank frame DUMMY. In this case, the corresponding User Speed is 8/9 * 3 * 14.4 kbit / s = 38.4 kbit / s as required. The corresponding information rate, which includes user data plus status and control, etc., transmitted over the radio interface when ·: 25 is operated with an E-TRAU frame specific, is 8/9 * 3 * 14.5 kbit / s = 38.666 ... kbit / p.

The E-TRAU frame contains 290 information bits (14,500 bps: 50). The header, control, synchronization, etc. information related to the E-TRAU frame is illustrated by the header field H.

Figure 5B illustrates the downlink radio frames transmitted by the BTS over the radio interface to the mobile station MS. The header H generally represents all information, such as header, control, synchronization, etc., in the radio frame. In addition to the header H, the radio frame must have enough bits to transmit the payload information. At least one bit of each 20 ms radio frame is required for the phase indication P1, P2 and P3 according to the invention. This implies the need for an additional Cap-35 bandwidth of at least 50 bit / s. Thus, the required radio interface rate is at least 38,666 + 0.050 = 38.71666 ... kbit / s. This must be rounded up 105752 12 so as to avoid the occurrence of fractional bits in the 20 ms outframe. In this example, the radio interface rate is selected to be 38,800 kbit / s. The radio interface rate of 38,800 kbit / s corresponds to 776 information bits for each 20 ms radio frame (38,800 bit / s: 50). The ratio of the number of information bits of the radio frames to the number of information bits of the E-TRAU frame is 776/290. This is slightly larger than 8/3, which means that the three radio interface frames can carry the information of the 8 E-TRAU frames plus a few extra bits.

For example, in the example described herein, the modulo 103 radio frame sequence would be effective. The three radio frames then carry 3 * 776 = 2328 bits. Correspondingly, 8 E-TRAU frames carry 8 * 290 = 2320 bits. Thus, the sequence of the three radio frames has eight additional bits for other purposes (2328 to 2320 bits). In the example of Figure 5B, frame numbering is chosen as the phase indication, with two bits in each radio frame being used for frame indication. The two bit positions in each of the three radio frame sequences are extra and need to carry padding information. In Figure 5B, these fill bits (e.g., 11) are placed at the end of the last frame.

This results in the sequence of the three radio frames 20 of FIG. 5B, each frame including a phase indication P1 = 00, P2 = 01, and P3 = 10. The first radio frame contains the contents lt and l2 of two full E-TRAU frames and slightly more than two thirds of the l31 E-TRAU frame l3. The remainder of the l32 from the E-TRAU frame l3 is located in the second radio frame. In addition, the second radio frame contains the contents of two complete E-TRAU frames * · 25 l4 and l5, and just over one third of the E-TRAU frame l6. The remaining two thirds 162 of the E-TRAU frame 16 are placed in the third radio frame. In addition, the third radio frame includes the contents of two whole E-TRAU frames i7 and l8 and two fill bits. After this, a new modulo 3 radio frame sequence begins.

Figures 6A and 6B illustrate the operation * of a mobile station MS in a downlink direction. The MS receives the downlink radio frames (Fig. 6A) as shown in Fig. 5B. Assume that the MS receives the first radio frame of the frame sequence. The MS examines the phase indication field P1 in the radio frame to determine what the radio frame in the frame sequence is and how the information units in the radio frame begin. The origin of the information units may be stored in each of the MSs in the frame sequence 13 105752

for the frame, e.g. P1 = 00: first unit at bit position 3, second unit at bit position 293, third unit at bit position 583, etc. Thus, since P1 = 00, the MS knows that this is the first frame of the frame sequence. In this case, the MS also knows that the 290 bits following the phase indication field P1 contain the en-5 first whole information unit I · ,, 290 next bits contain the second whole information unit I2 and the last bits 194 contain the third information unit. The MS then receives the next radio frame and analyzes the PF. Since P2 = 01, the MS knows that this is the second radio frame of the modulo 3 frame sequence. The MS 10 then knows that the phase indication field P2 is followed by the 96 bit information unit part l32, which is to be connected to the information unit part l31 received in the first radio frame. The MS performs the merge and produces an entire information unit 13. The 290 bits following the information unit part l32 include the entire information unit 14 and the 290 bits following the 290 unit include the entire information unit 15. The last 100 bits of the second frame include the information unit portion 161. The MS then receives the third frame of the radio frame sequence and analyzes the phase indication field P3. Since P3 = 10, the MS knows that this is the third frame of the modulo 3 radio frame sequence. In this case, the 190 bits immediately following the phase indication field P3 include a portion 162 of the sixth information unit which should be associated with the portion 161 received in the previous frame. The MS performs the merge and produces an entire information unit le. The next 580 bits include the seventh and eighth complete information units 17 and 18. The MS discards the last two bits of the radio frame, which are padding bits. Thus MS

'· 25 has returned eight information units I, - 18 for further processing. In normal operation, the next radio frame received by the mobile station MS is the first frame of the next modulo 3 frame sequence, whereby the above operation is repeated.

In the uplink direction, the operation is inverted but otherwise identical to the one shown above (in Figures 5A, 5B, 6A and 6B, the directions of the arrows are changed • ______ ..

'opposite). In other words, the MS compresses each of the information unit stream of Figure 6B into each of the uplink radio frames of Figure 6A and provides them with phase indication according to the invention. The base station BTS receives the uplink radio frames according to Figs. 35B and 6A and extracts the whole information units from the hi as described above for the mobile station MS for the downlink direction.

105752 The BTS compresses the separated information units into the contents of the E-TRAU frames, resulting in an uplink E-TRAU frame of FIG. 5A, which is transmitted to the network adapter IWF. Although in the context of Figures 5A, 5B, 6A and 6B, the information unit is the content of the E-TRAU frame, the information unit may consist of any information 5 that is to be transmitted. In a GSM system for non-transparent transmission, this unit may be the frame of a radio link protocol (RLP). In transparent data transmission, the information unit may be a V.110 frame or a group of multiple V.110 frames.

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. The invention and its embodiments are thus not limited to the examples described above, but may vary within the scope of the claims.

• · m m

Claims (15)

15 105752 A data transmission method in a digital communication system, comprising the steps of placing the information units to be transmitted in frames of the lower protocol 5 of the transmission, transmitting frames over the transmission, separating said information units from frames received over the transmission, characterized by: a phase indication, which is modular N and defines the sequence of N frames, a2) inserts in each modulo N frame sequence N1 an information unit where N1 is different from N, B) said separation step comprises steps 15 b1) identifying the phase and information of the modulo N frame sequence. b2) extracting the N1 information unit from each modulo N frame sequence for further processing. 2. Förfarande enligt patentkrav 1, telecommendation for telecommunicationsystem and telecommunicationsystem and attenformationsenheterna överförs i radioramar över radiogränssnittet. A method according to claim 1, characterized in that the communication system is a wireless communication system and that the information units are transmitted in the paging frames over the radio interface. 3. Förfarande enligt patentkrav 1 eller 2, kännetecknatavatt Such fasindikering omfattar en av feljande: en pseudo-bruskod, som är spridd över N radioramar; och ett sequencer. 25 4. Förfarande enligt patentkrav 1, 2 eller 3, kännetecknatav att fasindikeringen code som skydd mot överföringsfel. A method according to claim 1 or 2, characterized in that said phase indication comprises one of the following: a virtual noise code spread over the NDframe; and sequence number. Method according to claim 1, 2 or 3, characterized in that the phase indication is encoded as a protection against transmission errors. 5. Förfarande enligt patentkrav 1, 2, 3 eller 4, kännetecknat av attne informatenenhet i överföringsram, i flashing data överförs över nätgränssnittet mellan et radioaccessnätelement och en nätadapter. 30 6. Förfarande enligt patentkrav 1,2,3 eller 4, kännetecknat av attnder informationsenhet and informationsinnehallet i överföringsramen, * som överförs över nätgränssnittet mellan et radioaccessnätelement och en nätadapter. Method according to claim 1, 2, 3 or 4, characterized in that said information unit is a transmission frame in which data 30 is transmitted over a network interface between a radio access network element and a network adapter. A method as claimed in claim 2, 3 or 4, characterized in that said information unit is the information content of a transmission frame which is transmitted over a network interface between a radio access network element and a network adapter. 105752 16 7. Förfarande enligt patentkrav 1, 2, 3 eller4, kännetecknat 35 av att Such information may be provided in the protocol or the protocol may be annotated. 105752 20 A method according to claim 1, 2, 3 or 4, characterized in that said information unit is a protocol data unit of a higher level protocol. 8. Förfarande enligt patentkrav 7, a call protocol for this information and protocol data, a radio protocol, and a protocol for the mobile station. 9 9. Förfarande enligt patentkrav 6, kännetecknat av att nämn da placeringssteg omfattar steg, colors a1) 38,4 kbit / s standardized overhead 14,4 kbit / s overhead 16 kbit / s channeler vid nätgränssnittde, övver var ningsgrund a fictive ram, 10 a2) 20 ms radioramarna förses med fasindikering, blinking a modulo N, color N> 3, a3) N1 overexpression information informehäll placer i shade modulo N radioresquence, color N1> 8, a4) fyllnadsbitar placeras vid behov i slutet av den sista radioramen 15. i shade radio frequency sequence, such as anpassningssteg omfattar i mottagningsänden steg varvar b1) fasen för modulo N radio frequency sequence och överföringsra-marnas utgängspunkter i radvaramnafv1fv1vnfv2vnrvnfnfnrnfnfnfnf för vi- dare behandling, b3) avvisas of this fyllnadsinformation. A method according to claim 7, characterized in that said information unit is a protocol data unit, such as a radio link protocol frame, of a link protocol set up between the mobile station and the Network Adapter. A method according to claim 6, characterized in that said placement step comprises 10 a1) transmitting 38.4 kbit / s user data in 14.4 kbit / s transmission frames through three 16 kbit / s channels in a network interface which, when the ninth transmission frame is a fake frame, a2 ) providing 20 ms radio frames with phase indication, which is modulo N, where N> 3, 15 a3) inserting information content of transmission frame in each modulo N radio frame sequence N1, where N1> 8, a4) inserting the last interleaving N of each radio frame sequence, if necessary comprising, at the receiving end, steps 20b1) identifying a phase of each modulo N radio frame sequence and starting points of transmission frames in the radio frames based on said phase information, b2) extracting N1 transmission frame from each radio frame sequence for further processing, 25b3) discarding said padding information. 10. Förfarande enligt nägot av föregäende patentkrav, address-ecknat av att 25 en eller flera fyllnadsbitar tillaggs account ramsekvensen, förmänligt i slutet av den sista ramen, ifall det av N1 informationsenheten och fasinformation antalet bert informationsbitar i modulo N ramsekvensen, nämnda en eller flera fyllnadsbitar avvisas i mottagningsänden. 30 11. Förfarande enligt face av föregäende patentkrav, verbat - tecknat av att en fjärrtranskodarenhet förfarand-snittet mellan radioaccessnätelementet och nätadaptern och att förfarandet omfattar yt-terligarefegsta nv förfarandet fjärrtranskodaren, överföringsramar av en andra typ används mellan fjärrtranskodaren och nätadaptern, 21 105752 överföringsramarna av den första typen converter account överförings-ramar av den andra typen och tvärtom i fjärrtranskodaren. Method according to one of the preceding claims, characterized in that one or more padding bits are added to the frame sequence, preferably to the end of the last frame, if the number of bits required by the N1 information unit and phase information is less than the total number of information bits of modulo N frame sequence. . 11. A method according to any one of the preceding claims, characterized in that, in the network interface, 35 A remote transcoder unit is located between the network adapter, and that the method comprises additional steps 17 105752 using first type transmission frames between said element and the remote transcoder, using second type transmission frames between the remote transcoder and network adapter, converting first type transceivers 12. Digitalt mobilkommunikationssystem, som omfattar en mobilstation (MS), radio access, cellular basics (BTS), radio-channel var-channel and radio-access, radio-access, radio. informationsenheterna frän de mottagna radio-ramarna, kännetecknatavatt A) placeringsmedlen omfattar 10 med för att förse such radioramar med fasindikering (P1, P2), som modulo N och bestämmer N radioramens sequence, med för att Placera N1 informationsenheter 1 ^) i shield modulo N radio sequence, color N1 intact med N, B) avskiljningsmedlen omfattar 15 med för att identifera fasen f shield modulo N radio frequency sequence (^ ... IN1) utgängspunkter i radioramarna pä basis av nämnda fas P1, P2), for example N1 informationsenheter (l., ... lN1) frän shield modulo N radio frequency sequence f r treatement further on. 12. A digital mobile communication system comprising a radio interface between a mobile station (MS), a radio access network element such as a base station (BTS), a mobile station and a radio access network element using channel coding and radio frames, means for transmitting, transmitting, in the mobile station and in said radio access network element for distinguishing information units from received radio frames, characterized in that: 15 A) the positioning means comprises means for providing said radio frames with a phase indication (P1.P2) which is modulo N and determines N radio frames N1 information units (1, ... 1 ^), where N1 is different from N, B) the separating means comprising means for identifying the phase of each modulo N radio frame sequence and the starting points of the information units (l, ... lN1) on the basis of said phase information (P1.P2) in the radio frames, means for distinguishing N1 information units (l, ... lN1) 25 modulo N radio frame sequences for further processing. 13. System enligt patent krav 12, k n e t e c k n a t av att nämnda fasindikering (P1, P2) omfattar en av feljande: en pseudo-bruskod, som är utspridd över N radioramen; och ett sequencer. A system according to claim 12, characterized in that said phase indication (P1.P2) comprises one of the following: a pseudo-noise code spread over N radio frames; and sequence number. 14. System enligt patentkrav 12 eller 13, kännetecknatavatt nämnda informationsenhet (I, ... IN1): - 25. en överföringsram i flowing data överförs över et nätgränssnitt mellan radioaccessnätelementet (BTS) och nätadaptern (IWF), en överföringsram som överförs över et nätgränssnitt mellan radioaccessnätelementet (BTS) och nätadaptern (IWF), - en protocol dataenhet i prot protocol av högre niva, 30. en protocoldataenhet, säsom en radiolänk protocollram, för ett länkprotät The IWF). _________ A system according to claim 12 or 14, characterized in that said information unit (11 to 1N1) is one of the following: - A transmission frame in which data is transmitted over a network interface by a radio access network element (BTS) and a network adapter (IWF). ), - the transmission frame to be transmitted over the network interface between the radio access network element (BTS) and the Network Adapter (IWF) information content, - the higher level protocol protocol data unit, 18 105752 - the link between the mobile station (MS) and the Network Adapter (IWF), such as the radio link protocol frame. A system according to any one of claims 12, 13 or 14, characterized in that the insertion means are arranged to insert said one or more padding bits in the frame sequence, preferably at the end of the last frame if the number of bits required by the N1 information unit and phase information is 19 105752 '1. Förfarande för överföring av data i ett digitized telecommunicationsystem, flickering förfarande omfattar steg color informationsenheter som ska överföras placeras i ramar av et sl-5 re protocol i transmissionslänken, ramarna överförs över transmissionslänken n, transmissionslänken mottagna ramarna, kännetecknatavatt A) such placerlngssteg omfattar steg, colors 10 a1) such ramar förses med fasindikering, som modulo N ooh bestämmer en sequence av N ramen, a2) N1 informationsenheter placeras i1 varri n. med N, B) such avskiljningssteg omfattar steg, varvid 15 b1) fasen för varö modulo N ramsekens och informationsenheter- nas utgängspunkter i ramarna identifieras b2) N1 informensenheter avskiljs fr varje förens modulo N ramsekv. 15. System enligt face av patentkraven 12, 13 eller 14, call -tecknat av att placeringsmedlen et anordnade att tillagga en ener 35 flera fyllnadsbitar account rams sequen, förmänligt i slutet av den sista ramen, ifall det av N1 informationsenheten och fasinform antalet bitar är, mindre än det total antalet informationsbitar i modulo N ramsekvensen.