TDMA point-to-multipoint transmission network with a multiframe which includes a single continuous stream of data subframes and a single free period for response-time measurements

• US 5,712,982 A
• Filed: 09/20/1995
• Issued: 01/27/1998
• Est. Priority Date: 09/23/1994
• Status: Expired due to Fees

• Current Assignee: Alcatel-Lucent France, SA (Nokia Corporation)
• Original Assignee: Alcatel-Lucent France, SA (Nokia Corporation)
• Inventors: Marcel, Fran.cedilla.ois
• Primary Examiner(s): Lee, Thomas C.
• Assistant Examiner(s): KIM, KI S
• Application Number:
  US08/531,105
• Time in Patent Office: 860 Days
• Field of Search: 370/462, 370/362, 370/249, 370/250, 370/257, 370/503, 370/442, 370/508, 370/510, 395/200.17, 395/200.13, 395/200.19
• US Class Current: 709/236
• CPC Class Codes: H04J 3/0682 by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging

Abstract

In a time division multiple access point-to-multipoint transmission network, data is transmitted from a central station to local stations in multiframes containing a plurality of frames and a single free period allowing transmit time measurements and reflectometry measurements. Data is transmitted from the local stations to the central station in the form of multiframes containing a plurality of frames and a single free period allowing transmit time measurements and reflectometry measurements, each frame including subframes sent by the local stations, and each local station sending one or more of the subframes contained in a frame. The multiframes are constructed in a way that underuses the data sources, to obtain free periods between the frames, and by time-shifting the frames to construct a single free period per multiframe. Applications include telecommunication networks.

Claims

1. Time division multiple access point-to-multipoint transmission network including a central station and a plurality of local stations;

each local station including means for sending return multiframes including a plurality of return frames and a single free period having a duration allowing measurements to be made, each return frame including a plurality of return subframes each having a fixed duration and containing data sent by that local station only and addressed to said central station, return subframes being sent at predetermined times decided on by transmit time measurement means so that subframes sent by all said local stations are received by said central station without overlapping and constitute a return frame;

said central station including means for sending forward multiframes including a plurality of forward frames and a single free period having a duration allowing measurements to be made;

wherein, in said central station and/or at least one local station, said means for sending multiframes include;

means for sampling from a data source a series of data packets, two consecutive packets being separated by a free period, and for inserting each packet into a frame, two consecutive frames being separated by a free period; and

time-shift means for inserting a predetermined number of frames into a multiframe, time-shifting said frames to eliminate the free periods between them and thus to constitute a multiframe including a single continuous stream of time-shifted frames and a single free period.

2. The transmission network of claim 1 wherein said time-shift means include sufficient memory for storing at least a number of bits corresponding to said single free period.

3. The transmission network of claim 1 wherein said time-shift means include a dual-port memory having an input clock and output clock, said memory input clock is disabled for each said free period between said consecutive frames, and said memory output clock is periodically disabled for a duration equivalent to said single free period accumulated from a predetermined number of said free periods between said consecutive frames.

4. The transmission network of claim 3 wherein said memory further comprises a FIFO including:

a serial-to-parallel converter, a parallel-to-serial converter, and control means for controlling said converters and memory such that an input bit stream is converted to a parallel stream, stored into and read from said dual-port memory, and then converted back to an output bit stream according to said input clock and said output clock.

5. A time division multiple access point-to-multipoint transmission network including a central station and a plurality of local stations connected to a common transmission path;

said central station including means for sending forward frames, said forward frames each including a single free period having a duration allowing response-time measurements to be made;

each local station including means for sending return frames, said return frames each including a plurality of subframes and a single free period having a duration allowing response-time measurements to be made;

wherein each subframe is sent by a respective local station at a predetermined time relative to a frame start time, said predetermined time being adjusted according to said response-time measurements for said each respective local station; and

wherein said means for sending forward frames and means for sending return frames include;

means for building a shift frame comprising a single free period and a plurality of input data subframes clocked from a data source with free periods inserted between each two consecutive input data subframes; and

time-shift means for storing a predetermined number of bits of consecutive shift frames, accumulating the free period of each said shift frame, and generating a multiframe including a single continuous stream of time-shifted shift frames and a single accumulated free period.

6. The transmission network of claim 5 wherein said time-shift means include a FIFO memory having an input clock and an output clock, and sequentially storing a predetermined number of bits of said shift frames using said input clock, said output clock being enabled for a predetermined number of said shift frames, and then disabled for a time corresponding to said predetermined number of shift frames.

7. The transmission network of claim 6 wherein said predetermined number of bits is determined by the free period in each shift frame.

8. The transmission network of claim 6 wherein said FIFO memory includes sufficient memory for storing at least a number of bits corresponding to said accumulated free period.