Air interface statistical multiplexing in communication systems

Details Air interface statistical multiplexing in communication systems Air interface statistical multiplexing in communication systems

1998-02-02

2001-01-30

Olms, Douglas W. (Department: 2732)

Multiplex communications

Communication over free space

Having a plurality of contiguous regions served by...

C370S232000, C370S235000, C370S252000, C370S465000

Reexamination Certificate

active

06181684

ABSTRACT:

FIELD OF THE INVENTION
This invention relates generally to the field of multiple access techniques for communication systems. More specifically, this invention relates to a method and apparatus for statistical multiplexing for a wireless communication system.
BACKGROUND OF THE INVENTION
Conventional multiplexing techniques, such as for example, TDM (time-division multiplexing) make inefficient use of bandwidth in communication networks for certain applications (such as “bursty” input streams) because assigned time or frequency slots often go unused. Statistical multiplexing can be used to overcome these inefficiencies.
In statistical multiplexing, a communication link is multiplexed between channels on a probabilistic basis. With a large number of bursty connections, all of the connections may be assigned to the same link with a high probability that they will not all burst information at the same time. If they do burst simultaneously, the burst can be placed in a physical buffer until a free time slot becomes available. Statistical multiplexing allows the sum of the peak bandwidth requirement of all connections to a link to exceed the aggregate available bandwidth of the link under certain conditions. Statistical multiplexing schemes generally provide for smaller average delays on a per-packet basis than TDM or FDM (frequency-division multiplexing). Statistical multiplexing is a distinguishing feature of ATM (asynchronous transfer mode) networks. Through the use of statistical multiplexing, significantly more users can be serviced than without statistical multiplexing, thereby increasing profits of the system or network operator.
Classic wire-based communication networks have long taken advantage of statistical multiplexing to increase network capacity in terms of the number of system users who are able to access the system simultaneously.
FIG. 1
illustrates a prior art statistical multiplexer in a classic application. Several communication sources
100
, 1-n in the example in
FIG. 1
, are connected to multiplexer
110
by separate lines or wires
120
. Each line
120
has a capacity C
i
, where C
i
is greater than or equal to the full capacity of the source
100
it connects to multiplexer
110
. The transmission capability of outgoing line
130
from multiplexer
110
has a capacity C
out
<C
T
where C
T
is equal to the sum of all incoming transmission lines. If each source
100
transmits information or data continuously to another network node, such as network node
140
, much of the information from one or more of the sources will be lost because the outgoing capacity is less than the total incoming capacity. However, if each or at least most, of sources
100
are statistical in nature, that is arrival of information from the source is bursty in nature, the statistical multiplexer will be able route nearly all of the incoming information to outgoing transmission line
130
.
As information arrives randomly from each of sources
100
, it is placed in a buffer
150
. Processor
160
executes one or more multiplexing (“MUX”) algorithms. Multiplexer
110
has one buffer
150
for each of input lines
120
. Multiplexer
110
monitors the status of each buffer
150
, transferring data from the buffer with the greatest occupancy to outgoing transmission line
130
for transmission to node
140
. As a first buffer empties, a next buffer is switched to transfer data to outgoing line
130
. In this manner the statistical multiplexer allows outgoing transmission line
130
to have less capacity than the sum of the capacity of all incoming transmission lines
120
. This can represent a significant gain in efficiency for a communication system.
To date, the benefits of statistical multiplexing discussed above with respect to wire-based networks have not been fully realized in wireless networks taking advantage of the wireless interface. Multiplexing is generally done by establishing one-to-one links between the nodes of the system and combining individual sources in a multiplexer at the receiver end of the node.
What is needed is a method and apparatus to provide efficiency gain in wireless communication systems similar to that achievable through statistical multiplexing in wire-based communication systems. What is further needed is a method and apparatus to allow for improved efficiency gain in a communication system where system users (sources) are geographically distributed. What is further needed is a method and apparatus to allow for varying levels of quality of service (QoS) in a communication system which employs statistical multiplexing.


REFERENCES:
patent: 4730305 (1988-03-01), Acampora et al.
patent: 5293382 (1994-03-01), Carson et al.
patent: 5533009 (1996-07-01), Chen
patent: 5602836 (1997-02-01), Papadopoulos et al.
patent: 5648958 (1997-07-01), Counterman
patent: 5768254 (1998-06-01), Papadopoulos et al.
patent: 5991292 (1999-11-01), Focsaneanu et al.
patent: 6005856 (1999-12-01), Jensen et al.
patent: 6018528 (2000-01-01), Gitlin et al.

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