Arrangement for defining a transmission delay in a subscriber ne

Details Arrangement for defining a transmission delay in a subscriber ne Arrangement for defining a transmission delay in a subscriber ne

1996-03-08

1999-04-27

Patel, Ajit

Multiplex communications

Communication techniques for information carried in plural...

Combining or distributing information via time channels

455502, H04J 306

Patent

active

058986979

DESCRIPTION:

BRIEF SUMMARY
BACKGROUND OF THE INVENTION

The invention relates to an arrangement for determining a transmission delay in a subscriber network.
The solution according to the invention is especially suitable for a measurement of timings of uplink messages (from a subscriber towards a central unit) of a point-to-multipoint network implemented by time-division technique. Such networks can be, for instance, combined cable television and telephone networks, so-called Passive Optical Networks (PONs) and wireless local loops.
In known subscriber networks based on the time-division technique, no subscriber-terminal-specific measurement of transmission delay is needed, for the connections are point-to-point connections. When the time-division technique is used in combined cable television and telephone networks or PONs, it is necessary to have a transmission delay for each subscriber terminal under control, because of the multipoint character of the connections. This means that a procedure of some kind has to be arranged in such a network for measuring the subscriber-specific transmission delay so that the subscriber terminals are able to learn the correct moments of transmission.
One known method of measuring a transmission delay is based on the looping of the signal to be transmitted outside an actual transmission channel. In these arrangements, the delay is measured by monitoring an own message, which is looped back from the other end of the connection. The transmission takes place outside the actual transmission channel, on a channel especially allocated for delay measurement. The looping can be made at the midpoint of the point-to-multipoint network, in which case a subscriber terminal measures the delay, or the subscriber terminal can be connected to form a loop, in which case a device at the midpoint of the network measures the loop delay.
Another known method of measuring a loop delay is a measurement to be performed on the actual transmission channel. Then, to a payload signal is added a low-level slow-changing message of DS-spread-spectrumsignal type (DS, standing for direct sequence), which message can be detected on the reception side by means of a specific correlation receiver. A low-level signal does not interfere a data transmission on the same channel, but allows a determination of the loop delay anyway.
Drawbacks of the known measuring methods are, e.g., separate device arrangements required, which make the equipment more complicated than before, and also the transmission capacity needed, which makes the bandwidth left for actual utility purposes smaller. A further drawback of the measurements to be performed outside the actual transmission channel is that the delay may vary in different frequency ranges.


SUMMARY OF THE INVENTION

The object of the present invention is to provide a novel solution for the measurement of a delay, not showing the above-mentioned drawbacks. This is achieved by means of the arrangement according to the invention, which is characterized in.
The idea of the invention is to determine a value representing a delay of a subscriber terminal in a central unit of a subscriber network on the basis of the location (measured with respect to frame structure) of a message burst sent by the subscriber terminal to a common message channel. It shall be noted that the value representing transmission delay is of interest in this connection, because the absolute value of the delay need not be determined, and cannot be determined either, because of different processing and other delays (the exact value of which is not known) relating to a loop delay.
By means of the solution according to the invention, a simple and quick method is achieved, which is also capable of utilizing the transmission capacity efficiently.
Since a transmission delay can be measured, by using the method of the invention, without any specific arrangements from a normal signalling message or the like required by telephone traffic, the equipment can be maintained as simple as possible. A delay measurement may be performed entirely

REFERENCES:
patent: 4086537 (1978-04-01), Asakawa et al.
patent: 4481648 (1984-11-01), Fugii
patent: 4519068 (1985-05-01), Krebs et al.
patent: 4815110 (1989-03-01), Benson et al.
patent: 5027426 (1991-06-01), Chiocca et al.
patent: 5124980 (1992-06-01), Maki
patent: 5228030 (1993-07-01), Backstrom et al.
patent: 5229996 (1993-07-01), Backstrom et al.
patent: 5258981 (1993-11-01), Davey et al.
patent: 5317571 (1994-05-01), Marcel et al.
patent: 5363373 (1994-11-01), Nakahara et al.
patent: 5748621 (1998-05-01), Masuda et al.

Affiliated with

Also associated with

Rating

Arrangement for defining a transmission delay in a subscriber ne does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Arrangement for defining a transmission delay in a subscriber ne, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Arrangement for defining a transmission delay in a subscriber ne will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-690364