MXPA99000408A - Apparatus and method for mapping telecommunication signals e1 to a suscrip bus - Google Patents

Abstract

In a subscriber circuit equipment having a subscriber bus, a data stream is provided by not carrying a first set of data time slots of an E1 signal and a first set of signal time slots and control of the E1 signal, and an even data stream carrying a second set of data time slots of signal E1 and a second set of signal time slots and control of signal E1. The data streams non and couple are interleaved bit and are transported over the bus or suscript

Description

APPARATUS AND METHOD FOR MAPPING TELECOMMUNICATION SIGNALS THE A SUBSCRIBER BUS TECHNICAL FIELD OF THE INVENTION This invention relates in general to the field of telecommunications systems. More particularly, the invention relates to an apparatus and method for mapping telecommunications signals onto a subscriber bus.

BACKGROUND OF THE INVENTION In the early days of telecommunication, a copper wire medium was used to carry a single information channel. Because the greater proportion of cost is in the materials and in the construction of the physical link, telephony engineers have developed ways to pack multiple channels into a single physical link. Frequency division multiplexing (FDM) and time division multiplexing (TDM) have been designed for multiple multiplex streams of digital pulse code modulation (PCM) signals, respectively, in one. For digital signals, the time division multiplex hierarchy is DSO to DS4, where DSO is a single 0.064 Mbps channel, a DS1 is 24 DSOs multiplexed together, and a DS4 is 4,032 DSOs multiplexed together.

A similar time division multiplexing scheme is used in international telephone systems based on the 32-channel format, where each channel is occupied by a DSO signal. International digital systems, based on the recommendations of the G.700 series of the International Telecommunication Union CCITT's are commonly called El or CEPT-1. The El signals are based on blocks of 32 channels or time slots, of which the time slot 0 and the time slot 26 are typically used for control and signaling, respectively.

American telecommunications equipment manufacturers eager to compete in the international arena must design and produce equipment that operates under the international standard. Alternatively, in order to achieve compatibility, telecommunications equipment which was originally designed and manufactured to handle signals under American standards must be modified to accommodate international signals.

SYNTHESIS OF THE INVENTION Therefore, there is a need to provide a subscriber circuit equipment that is compatible with international standards, such as the transport of the El signal.

In one aspect of the invention, in a channel bank having a subscriber bus having a time slot frame thirty two, a data stream is provided not carrying a first set of data time slots of a signal El and a first set of time slots for control and signaling of the signal El, and an even data stream carrying a second set of data time slots of the signal El and a second set of time slots for control and signaling The El signal. The odd and even data streams are bit interchanged and transported over the subscriber bus.

In another aspect of the invention, a method for mapping the signals El onto a subscriber bus includes the steps of mapping a first set of data channels of the signals El over the predetermined time slots of a first data stream, and mapping a first set of signaling and control channels of the signals on other predetermined time slots of the first data stream. Also included are the steps of mapping a second set of data channels of the signals El over the predetermined time slots of a second data stream, and mapping a second set of signaling and control channels of the signals. other predetermined time slots of the second data stream.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the present invention, reference is now made to the accompanying drawings in which: Figure 1 is a top-level block diagram of an exemplary channel bank unit constructed in accordance with the teachings of the present invention.

Figure 2 is a diagram of an incorporation of a subscriber bus structure according to the teachings of the present invention.

Figures 3A and 3B are example mapping diagrams for the subscriber bus; Y Figures 4A and 4B are additional example mapping diagrams for the subscriber bus.

DETAILED DESCRIPTION OF THE INVENTION Preferred embodiments of the present invention are illustrated in Figures 1-4, like reference numbers being used to refer to like and corresponding parts of the various drawings.

Referring to Figure 1, a channel bank 10 constructed according to the teachings of the present invention is shown. The channel bank 10 is coupled to a digital circuit carrier 12 via a data message and control link 1. The digital circuit carrier 12 is in communications with the equipment residing in the central office (not shown), such as a central office terminal (not shown) and the digital circuit carrier and the digital cross connection system (not shown) ).

The channel bank 10 is a multiplexing equipment from DSO to DS1 or from DSO to El primarily used for the conversion of pulse code modulation (PCM) to analog speech and for multiplexing. The channel bank 10 includes a bank control unit (BCU) 20, which can be coupled to more than one channel unit (CU) 22 through a subscriber bus 26. The channel units 22 can operate at rates DS1 and DS3, as well as international rates such as El. A plurality of subscriber equipment 30 may be coupled to each channel unit 22.

The data carried on the subscriber bus 26 has the example format shown in Figure 2. Each frame includes 32 time slots or channels, eight of which are reserved or dedicated to signaling and control. In Figure 2, "R" denotes a reserved slot; "YES" through "S4" denote pointing time slots; "F" denotes framing, "SR" denotes a service request channel of communication systems; and "DL" denotes data link. In the signaling time slots of each frame, the arrow indicates the signaling time slots for the channels. The word structure for each time slot is also shown.

Subscriber bus 26 is comprised of two bit-interleaved data streams. Figures 3A and 3B show the data and the signaling format for the NONES and COUPLES data streams, which may be identical to carry two signals DS1. Note that "sig" denotes pointing time slots. The mapping scheme DS1 or Ti is described in the co-pending United States patent application entitled Method and Apparatus for Mapping Telecommunications Signals on a Subscriber Bus, Series No., filed on.

To accommodate the El signals, two data streams are required to carry the data and the signaling of an El signal, since it is composed of 32 data time slots. The example format for transporting the signal El by means of the data streams NONES and COUPLES of a subscriber bus is shown in figures 4A and 4B. Alternatively, the signal El can be transported over two odd data streams of the two subscriber buses. It can be seen that the channels are divided between the two data streams. In the embodiment shown in Figures 4A and 4B. Alternatively, the signal El can be transported over two 5 nones data streams of the two subscriber buses. It can be seen that the channels are divided between the two data streams. In the embodiment shown in Figures 4A and 4B, 24 channels are carried on the stream of; NON data, and eight remaining channels are carried by the COUPLE data stream. It can be seen that the exact mapping of the channels on the data streams may differ from that shown. In addition, it is contemplated that more than two data streams may be multiplexed together to form the subscriber bus 26.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (31)

R E I V I N D I C A C I O N S

1. In a channel bank that has a subscriber bus that has a box of 32 time slots that comprises: a data stream not carrying a first set of data time slots of a signal El and a first set of time slots for controlling and signaling the signal El; an even data stream carrying a second set of data time slots of the signal El and a second set of signal time slots and control of the signal El; Y the non and even data streams are interconnected with bits and are transported on the subscriber bus.

2. The channel bank as claimed in clause 1, characterized in that the data stream does not comprise data time slots 1-3, 5-7, 9-11, 13-15, 17-19, 21-23 , 25-27 and 29-31.

3. The channel bank as claimed in clause 1, characterized in that the time slots 1-3, 5-7, 9-11, 13-15, 17-19, 21-23, 25-27 and 29- 31 of the data stream does not comprise the data time slots 1-3, 5-7, 9-11, 13-15, 17-19, 21-23, 25-27 and 29-31, respectively.

4. The channel bank as claimed in clause 1, characterized in that the even data stream comprises the data time slots 0, 4, 8, 12, 16, 20, 24 and 28.

5. The channel bank as claimed in clause 1, characterized in that the time slots 1, 5, 9, 13, 17, 21, 25 and 29 of the even data stream comprise the time slots of data 0, 4, 8, 12, 16, 20, 24 and 28, respectively.

6. The channel bank as claimed in clause 1, characterized in that the data stream does not comprise the signaling and control time slots SRQ and DL.

7. The channel bank as claimed in clause 1, characterized in that the time slots 16 and 24 of the data stream do not comprise signaling and control time slots SRQ and DL, respectively.

8. The channel bank as claimed in clause 1, characterized in that the data stream does not comprise the signaling time slots S1-S4.

9. The channel bank as claimed in clause 1, characterized in that the time slots 4, 12, 20 and 28 are the data stream non comprising the signaling time slots S1-S4, respectively.

10. The channel bank as claimed in clause 1, characterized in that the even data stream comprises the signal time slots S1-S4.

11. The channel bank as claimed in clause 1, characterized in that the time slots 4, 12, 20 and 28 of the even data stream comprises the signaling time slots S1-S4, respectively.

12. A subscriber circuit equipment that has a bus that comprises: a data stream not carrying the data time slots 1-3, 5-7, 9-11, 13-15, 17-19, 21-23, 25-27 and 29-31 of the El signal and a first Set of signaling and signal control time slots; an even data stream carrying data time slots 0, 4, 8, 12, 16, 20, 24 and 28 of the signal El and a second set of time slots for signaling and control of the signal El; Y the non and couple data streams being interleaved with bits and transported on the bus.

13. The subscriber circuit equipment as claimed in clause 12, characterized in that the time slots 1-3, 5-7, 9-11, 13-15, 17-19, 21-23, 25-27 and 29 -31 of the data stream does not comprise the data time slots 1-3, 5-7, 9-11, 13-15, 17-19, 21-23, 25-27 and 29-31, respectively.

14. The subscriber circuit equipment as claimed in clause 12, characterized in that the time slots 1, 5, 9, 13, 17, 21, 25 and 29 of the even data stream comprise the data time slots 0 , 4, 8, 12, 16, 20, 24 and 28, respectively.

15. The subscriber circuit equipment as claimed in clause 12, characterized in that the data stream does not comprise the control and signaling time slots SRQ and DL.

16. The subscriber circuit equipment as claimed in clause 12, characterized in that the time slots 16 and 24 of the data stream do not comprise the signaling and control time slots SRQ and DL, respectively.

17. The subscriber circuit equipment as claimed in clause 12, characterized in that the data stream does not comprise the signaling time slots Sl-S4.

18. The subscriber circuit equipment as claimed in clause 12, characterized in that the time slots 4, 12, 20 and 28 of the data stream do not comprise the signal time slots S1-S4, respectively.

19. The subscriber circuit equipment as claimed in clause 12, characterized in that the even data stream comprises the signaling time slots S1-S4.

20. The subscriber circuit equipment as claimed in clause 12, characterized in that the time slots 4, 12, 20 and 28 of the even data stream comprise the signaling time slots S1-S4, respectively.

21. A method for mapping the signals on a subscriber bus having frames of thirty two time slots, comprising the steps of: mapping a first set of data channels of the signals El over the predetermined time slots of a first data stream; mapping a first set of signals signaling and control channels El over the other predetermined time slots of the first data stream; mapping a second set of the data channels of the signals El over the predetermined time slots of a second data stream; mapping a second set of the signaling and control channels of the signals on other predetermined time slots of the second data stream; Y intercalar with bit the first and second data streams.

22. The method as claimed in clause 21, characterized in that the first set of the data channel mapping step comprises the step of mapping the data channels 1-3, 5-7, 9-11, 13-15 , 17-19, 21-23, 25-27 and 29-31 on the predetermined time slots of the first data stream.

23. The method as claimed in clause 21, characterized in that the first set of the data channel mapping step comprises the step of mapping the data channels 1-3, 5-7, 9-11, 13-15 , 17-19, 21-23, 25-27 and 29-31 over time slots 1-3, 5-7, 9-11, 13-15, 17-19, 21-23, 25-27 and 29 -31, respectively, of the first data stream.

24. The method as claimed in clause 21, characterized in that the second set of the data channel mapping step comprises the step of mapping the data channels 0, 4, 8, 12, 16, 20, 24 and 28 over the predetermined time slots of the even data stream.

25. The method as claimed in clause 21, characterized in that the second set of the data channel mapping step El comprises the step of mapping the data channels 0, 4, 8, 12, 16, 20, 24 and 28 on the time slots 1, 5, 9, 13, 17, 21, 25 and 29, respectively, of the second data stream.

26. The method as claimed in clause 21, characterized in that the first set of the control and signal channel mapping step comprises the step of mapping the signaling channels SRQ and DL over the other predetermined time slots of the first data stream.

27. The method as claimed in clause 21, characterized in that the first set of the control and signaling channel mapping step comprises the step of mapping the signaling channels SRQ and DL over the time slots 16 and 24 of the signaling channel. first data stream.

28. The method as claimed in clause 21, characterized in that the first set of the control and signal channel mapping step comprises the step of mapping the signaling channels S1-S4 over the other predetermined time slots of the first data stream.

29. The method as claimed in clause 21, characterized in that the first set of the control and signal channel mapping step comprises the step of mapping the signaling channels S1-S4 over the time slots 4, 12, 20 and 28, respectively, of the first data stream.

30. The method as claimed in clause 21, characterized in that the second set of the control and signaling channel mapping step comprises the step of mapping the signaling channels S1-S4 over the other predetermined time slots of the second one. data stream.

31. The method as claimed in clause 21, characterized in that the second set of the control and signaling channel mapping step comprises the step of mapping the signaling channels S1-S4 over the time slots 4, 12, 20 and 28, respectively, of the second data stream. R E S U E N In a subscriber circuit equipment having a subscriber bus, a data stream is provided "not carrying a first set of data time slots of a signal El and a first set of signal time slots and signal control. , and an even data stream carrying a second set of data time slots of the El signal and a second set of signaling and control time slots El. The non and even data streams are interspersed with bit and they are transported on the bus or subscriber.