US5684802A
Expired / Lapsed
US
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System and method for hybrid contention/polling protocol collison resolution used backoff timers with polling
Assignee: Google Technology Holdings LLC
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Filing: 1995-05-02
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Granted: 1997-11-04
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Expires: 2015-05-02
Abstract
Abstract The system and method provide for efficiently resolving collisions in an environment where a transmitting device cannot hear collisions without a headend control station/control device, i.e., master, repeating transmission of all upstream frames in the downstream direction. This invention also prevents additional collisions from occurring between a device that is retransmitting and a device that is transmitting a packet for the first time. Further, the present invention allows continued utilization of a channel by other devices while contending devices are processing collision resolution procedures.
Inventors
- 👤 John A. Perreault
- 👤 Abhay Joshi
- 👤 Mete Kabatepe
- 👤 Lawrence W. Lloyd
- 👤 Stephen Schroeder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:07
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/40; H04L12/407; H04L12/413; H04L12/403
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
130 words
A simultaneous channel access system having a hybrid contention/polling protocol for resolving collisions between transmissions received by a control station/control device from a plurality of tributary devices, the system comprising: A) the control station/control device, operably coupled to receive the transmissions from the plurality of tributary devices, for utilizing the hybrid contention/polling protocol to resolve collisions between transmissions from the plurality of tributary devices; B) the plurality of tributary devices, operably coupled to send transmissions to the control station/control device, each tributary device having a retransmit/backoff timer for determining an expiration time before which the tributary device must remain silent when given an opportunity to retransmit by the control station/control device and after which the tributary device can retransmit when given the opportunity to retransmit by the control station/control device.
Claim 2
Dependent Claim
130 words
A simultaneous channel access system having a hybrid contention/polling protocol for resolving collisions between transmissions received by a control station/control device from a plurality of tributary devices, the system comprising: A) the control station/control device, operably coupled to receive the transmissions from the plurality of tributary devices, for utilizing the hybrid contention/polling protocol to resolve collisions between transmissions from the plurality of tributary devices; B) the plurality of tributary devices, operably coupled to send transmissions to the control station/control device, each tributary device having a retransmit/backoff timer for determining an expiration time before which the tributary device must remain silent when given an opportunity to retransmit by the control station/control device and after which the tributary device can retransmit when given the opportunity to retransmit by the control station/control device.
Claim 3
Dependent Claim
62 words
The simultaneous channel access system of claim 1 wherein the hybrid contention/polling protocol comprises the steps of: upon a collision being determined at the control station/control device: A) sending, by the control station/control device to the tributary devices, a collision resolution poll; B) upon receiving the collision resolution poll, retransmitting by each tributary device whose retransmit/backoff timer has reached its expiration time.
Claim 4
Dependent Claim
19 words
The simultaneous channel access system of claim 1 wherein the transmissions of the tributary devices include frames of data.
Claim 5
Dependent Claim
37 words
The simultaneous channel access system of claim 1 wherein the expiration times of the retransmit/backoff timers of the tributary devices are set to random time periods that are less than or equal to a predetermined timeout period.
Claim 6
Dependent Claim
145 words
The simultaneous channel access system of claim 1 wherein, upon sending a contention poll to the plurality of tributary devices authorizing a number of said tributary devices to transmit on the shared channel, the control station/control device receives one of: a null response indicating that none of the tributary devices transmitted; an ungarbled response indicating that exactly one of the tributary devices transmitted; and a garbled response indicating that transmissions from a plurality of tributary devices collided on the shared channel; and wherein: upon receiving the ungarbled response, the control station/control device sends an acknowledgement message to the tributary device indicating that the response was received by the control device; and upon receiving the garbled response, the control station/control device sends a collision resolution poll to the tributary devices authorizing any of the tributary devices whose retransmit/backoff timer has reached its expiration time to retransmit.
Claim 7
Dependent Claim
83 words
The simultaneous channel access system of claim 1 wherein, upon receiving a contention poll from the control station/control device authorizing the tributary device to transmit on the shared channel, the tributary device transmits one of: a data response, if the tributary device has data to transmit; and a silent response, if the tributary device has no data to transmit; and wherein: upon sending the data response, the tributary device starts its retransmit/backoff timer by setting the expiration time to a random timeout period.
Claim 8
Dependent Claim
119 words
A hybrid contention/polling protocol for resolution of collisions between transmissions received by a control station/control device from a plurality of tributary devices each having a retransmit/backoff timer for determining an expiration time before which the tributary device must remain silent when given an opportunity to retransmit by the control station/control device and after which the tributary device can retransmit when given an opportunity to retransmit by the control station/control device, comprising the steps of: upon a collision being determined at the control station/control device: A) sending, by the control station/control device, a collision resolution poll to the tributary devices; B) upon receiving the collision resolution poll, retransmitting by each tributary device whose retransmit/backoff timer has reached its expiration time.
Claim 9
Dependent Claim
119 words
A hybrid contention/polling protocol for resolution of collisions between transmissions received by a control station/control device from a plurality of tributary devices each having a retransmit/backoff timer for determining an expiration time before which the tributary device must remain silent when given an opportunity to retransmit by the control station/control device and after which the tributary device can retransmit when given an opportunity to retransmit by the control station/control device, comprising the steps of: upon a collision being determined at the control station/control device: A) sending, by the control station/control device, a collision resolution poll to the tributary devices; B) upon receiving the collision resolution poll, retransmitting by each tributary device whose retransmit/backoff timer has reached its expiration time.
Claim 10
Dependent Claim
18 words
The hybrid contention/polling protocol of claim 7 wherein the transmissions of the tributary devices include frames of data.
Claim 11
Dependent Claim
36 words
The hybrid contention/polling protocol of claim 7 wherein the expiration times of the retransmit/backoff timers of the tributary devices are set to random time periods that are less than or equal to a predetermined time period.
Claim 12
Dependent Claim
144 words
The hybrid contention/polling protocol of claim 7 wherein, upon sending a contention poll to the plurality of tributary devices authorizing a number of said tributary devices to transmit on the shared channel, the control station/control device receives one of: a null response indicating that none of the tributary devices transmitted; an ungarbled response indicating that exactly one of the tributary devices transmitted; and a garbled response indicating that transmissions from a plurality of tributary devices collided on the shared channel; and wherein: upon receiving the ungarbled response, the control station/control device sends an acknowledgement message to the tributary device indicating that the response was received by the control device; and upon receiving the garbled response, the control station/control device sends a collision resolution poll to the tributary devices authorizing any of the tributary devices whose retransmit/backoff timer has reached its expiration time to retransmit.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-11-03 | 2001-05-05 | 2001-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-11-03 | 2005-05-05 | 2005-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-11-03 | 2009-05-05 | 2009-11-04 | $7700.00 | Window Closed / Lapsed |