Multiplex communications – Communication techniques for information carried in plural... – Adaptive
Reexamination Certificate
2000-03-20
2004-03-16
Pham, Chi (Department: 2667)
Multiplex communications
Communication techniques for information carried in plural...
Adaptive
C370S494000, C455S416000
Reexamination Certificate
active
06707826
ABSTRACT:
FIELD OF THE INVENTION
The present invention is directed to multi-way calling, and more particularly to a bandwidth efficient method and apparatus capable of handling multiple simultaneous callers in a wireless communication system.
BACKGROUND OF THE INVENTION
Typical three-way calling having at least one mobile wireless subscriber is either typically bandwidth inefficient or poor in voice quality or both. Such inefficiencies can be illustrated in a digital communication system where a three-way call needs to be set up between a mobile user “M” and two other users “A” and “B”. Users “A” and “B” can either be mobile units, PSTN users or Voice-over-Internet Protocol (VoIP) users. Focusing on M's wireless connection to a base station, a three-way call can be set-up simply by allocating two downlink channels (one for “A” and one for “B”) and allocating one uplink channel for the mobile user “M”. The disadvantage of this approach is that it requires 1.5 times the bandwidth as a normal two-way conversation.
An alternative to the example above is to convert signals “A” and “B” back into analog voice waveforms, add the waveforms, and then re-code the composite waveform into a single downlink channel. This solves the bandwidth efficiency problem of the method above, but it adds additional complexity to the system in terms of the decoding and then re-coding of the voice information. Furthermore, Very Low Bit-rate (VLB) vocoders do not perform well when the input waveform consists of more than one voice. Therefore, combining the two voices from “A” and “B” followed by re-coding of the signal would degrade the call quality.
Thus a need exists for a bandwidth efficient method and apparatus that would allow for multi-party calls, preferably using a VLB adjustable vocoder with minimal impact on voice quality.
REFERENCES:
patent: 5881053 (1999-03-01), Kimball
patent: 5896565 (1999-04-01), Miller
patent: 6104726 (2000-08-01), Yip et al.
patent: 6185525 (2001-02-01), Taubenheim et al.
patent: 6424637 (2002-07-01), Pecen et al.
patent: 6563807 (2003-05-01), Kim et al.
Gorday Paul Edward
Satyamurti Sunil
Boakye Alexander O.
Karpinia Randi L.
Motorola Inc.
Pham Chi
LandOfFree
Method and apparatus for wireless bandwidth efficient... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for wireless bandwidth efficient..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for wireless bandwidth efficient... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3191590