Time multiplexed requests for controlling access to a shared communication medium

a technology of shared communication medium and multiplexing request, which is applied in the direction of multiplex communication, loop network, data switching network, etc., can solve the problems of still exist a probability of collisions and the performance of the system can be negatively impacted

Inactive Publication Date: 2008-08-07
VIASAT INC
View PDF11 Cites 27 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The present invention relates to methods and apparatuses for conducting communications over a shared communication medium involving a plurality of nodes. The invention involves sending a request from a first node in the plurality of nodes, receiving an assignment associating the request with a scheduled transmission segment selected from a plurality of scheduled transmission segments, and sending a data transmission in the scheduled transmission segment associated with the request. The invention allows for efficient communication over a shared communication medium and ensures that multiple nodes can communicate with each other without interference.

Problems solved by technology

Even though a node listens first before transmitting, there still exists a probability for collisions.
If the reservation process itself occupies too much of the shared communication medium, performance of the system can be negatively impacted.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Time multiplexed requests for controlling access to a shared communication medium
  • Time multiplexed requests for controlling access to a shared communication medium
  • Time multiplexed requests for controlling access to a shared communication medium

Examples

Experimental program
Comparison scheme
Effect test

first embodiment

[0157]N-symbol requests are described in more detail below. Two separate embodiments are presented. a request comprising N symbols is non-coherently detected. That is, the recipient of the request (e.g., scheduler node 102, other access nodes such as 104, 106, 108, and 110) receives the request as a non-coherent signal. For example, the recipient may utilize an envelope detector that only detects each symbol of the request as either an “on” or “off.” Generally speaking, such an N-symbol request can specify one out of 2N−1 service types. In one implementation where each request comprises N=2 symbols, the request may support 3 different types of services as follows. If symbol 1 is “on” and symbol 2 is “off,” then service type 1 is indicated. If symbol 1 is “off” and symbol 2 is “on,” then service type 2 is indicated. If symbol 1 is “on” and symbol 2 is “on,” then service type 3 is indicated. Of course, if symbol 1 is “off” and symbol 2 is “off,” then no request is sent.

[0158]FIG. 15 ...

second embodiment

[0159] a request comprising N symbols is coherently detected. That is, the recipient of the request receives the request as a coherent signal. Designs of such coherent detectors are well-know in the art. The recipient may demodulate the request according to a particular modulation and / or coding scheme. One example is a system based on a differentially coherent detection scheme. Here, M-ary differential phase shift keying (M-DPSK) modulation is used. An N-symbol request can specify one of MN-1 different service types, with one symbol used to provide a phase reference. Furthermore, the M-DPSK signal may also be block-coded to provide error correction. Of course, this is just one example. In other implementations, different modulation and coding schemes may be used. The particular choice of modulation and coding scheme may be depend on channel conditions, such as the signal to noise ratio (SNR) encountered.

Default Assignment of Scheduled Transmission Segments

[0160]According to an embod...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

Methods and apparatuses are presented for conducting communications over a shared communication medium involving a plurality of nodes, involving (a) sending a request from a first node, the shared communication medium organized to include a request signal space and a scheduled transmission signal space, the request signal space including a plurality of request time slots each having a different location within the request signal space, the scheduled transmission signal space including a plurality of scheduled transmission segments each having a different location within the scheduled transmission signal space, the request sent in a request time slot that is one of the plurality of request time slots, (b) obtaining an assignment associating the request with a scheduled transmission segment, the assignment taking into account location of the request within the request signal space, and (c) from the first node, sending a data transmission in the scheduled transmission segment associated with the request.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS[0001]The present application claims benefit of priority under 35 U.S.C. 119(e) of U.S. provisional Application No. 60 / 888,451, filed on Feb. 6, 2007, entitled “Symbol Oriented Reservation Request System For Controlling Access To A Shared Communications Link,” Attorney Docket No. 017018-014000US, Client Reference No. VS-0239-US, the content of which is incorporated herein by reference in its entirety.[0002]The present application also claims benefit of priority under 35 U.S.C. 119(e) of U.S. provisional Application No. 60 / 895,143, filed on Mar. 16, 2007, entitled “Blip and Burst Multiple Access,” Attorney Docket No. 017018-014400US, Client Reference No. VS-0242-US, the content of which is incorporated herein by reference in its entirety.[0003]The following U.S. nonprovisional patent applications, including the present application, are being filed concurrently and the disclosure of every other application is incorporated by reference in the pre...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & AuthorityApplications(United States)
IPC IPC(8): H04L12/43H04J3/00H04L12/24
CPCH04B7/18582H04W84/06H04W72/1284H04W72/1273H04W72/21
InventorBECKER, DONALD W.
OwnerVIASAT INC