Method and apparatus for controlling access to a communication channel

• US 6,404,753 B1
• Filed: 09/04/1998
• Issued: 06/11/2002
• Est. Priority Date: 09/04/1998
• Status: Expired due to Fees

• Current Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.), AT&T Wireless Services Incorporated (AT&T, Inc.)
• Inventors: Chien, Herman, Leung, Kin K.
• Primary Examiner(s): MARCELO, MELVIN C
• Application Number:
  US09/148,316
• Time in Patent Office: 1,376 Days
• Field of Search: 370/329, 370/336, 370/337, 370/345, 370/347, 370/348, 370/442, 370/443
• US Class Current: 370/337
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 84/14 WLL [Wireless Local Loop]; RLL [Radio Local Loop]

Abstract

A method and an apparatus provide for controlled access to a shared communication medium. Time slots on a forward channel include information regarding status useful for remote units to determine whether a reverse channel is available for seizure. Additionally, information along the forward channel provides guidance to the remote units to control attempts to seize the reverse channel. In one embodiment a remote unit divides a data package into a plurality of portions and attempts to seize the reverse channel using a single portion of the data package which corresponds to one time slot on the reverse channel. It then waits until it receives notification along the forward channel that the first data portion was successfully received before it attempts to send any of the remainder of its data in consecutive time slots on the reverse channel.

Claims

1. A method for enhancing throughput in a data channel between a remote unit and a base unit in a wireless network, the method comprising the steps of:

receiving a first portion of a data package from the remote unit in a first time slot on said data channel;

changing a status flag in a time slot for transmission along a channel for communication to the remote unit;

at a time occurring subsequent to transmission of said time slot including the changed status flag;

receiving a second portion of said data package from the remote unit in another time slot on said data channel;

determining from said second portion an approximation of time needed to transmit a remainder of said data package; and

wherein when said approximation exceeds a predetermined value indicating a busy status using a status flag in another time slot along said channel for communication to said remote unit, and

when said approximation is less than a predetermined value, indicating a non-busy status using the status flag in said another time slot along said channel for communication to said remote unit.

2. The method of claim 1 wherein said predetermined value corresponds to a round trip time that represents the time needed for data in a time slot to be propagated to said base unit and processed by said base unit and for responsive data to be propagated from the base unit to the remote unit and processed at the remote unit.

3. The method of claim 1 wherein said step of determining includes detecting a state of a data length tag in said another time slot on said data channel.

4. A method for improving data throughput in a wireless network that includes a plurality of remote units, a base unit, a forward channel carrying information from said base unit to said plurality of remote units and a reverse channel, shared by the plurality of remote units for carrying information to the base unit, wherein said forward and reverse channels include a plurality of time slots, the method comprising the steps of:

detecting an idle status in a time slot on said forward channel;

forwarding a first portion of a data package in a first time slot on said reverse channel;

receiving an indication that said first portion has been successfully received by the base unit;

transmitting a second portion of said data package in a second time slot of the reverse channel that follows said first time slot by at least one round trip time interval, said interval corresponding to a time period that includes a time for propagating a time slot to the base unit on the reverse channel, a time for processing a time slot at the base unit and a time for propagating a response along said forward channel to the remote unit and processing the response at the remote unit;

wherein said second portion includes an approximation of a length of a remaining portion of the data package.

5. The method of claim 4 wherein said approximation includes a flag indicating whether the length of said remaining portion exceeds a predetermined length.

6. The method of claim 5 wherein said predetermined length corresponds to said round trip time interval.

7. The method of claim 4 wherein said indication that said first portion has been successfully received includes a successful decode flag on said forward channel in a time slot received at the end of the round trip interval after the transmission of said first portion of the data package.

8. A method for enhancing throughput in a data channel between a remote unit and a base unit in a wireless network, the method comprising the steps of:

at a remote unit,

detecting an idle status in a time slot received from the base unit,

transmitting a first portion of a data package in a time slot sent to the base unit,

delaying a transmission of a remainder of said data package until said remote unit receives an indication that it has successfully seized the data channel;

when the remote unit receives an indication that it has successfully seized the data channel transmitting a second portion of said other package to said base unit, said second portion including an indication of whether a remainder of said data package exceeds a predetermined number of time slots; and

at the base unit,

receiving said first portion, and

if the remote unit has successfully seized the data channel,

sending an indicator in a time slot to said remote unit,

receiving said second portion,

detecting said indication of whether the remainder of said data package exceeds said predetermined number of time slots, and

if said indicator indicates that the remainder of said data package does not exceed said predetermined number of time slots, transmitting an indicator of idle status in a time slot to the remote unit.

9. The method of claim 8 wherein said predetermined number of time slots correspond to a round trip time interval associated with the time it takes to propagate a time slot from the remote unit to the base unit, to process a received time slot at the base unit and to propagate a response time to the remote unit and process the response at the remote unit.

10. A method for improving data throughput in a wireless network that includes a plurality of remote units, a base unit, a forward channel carrying information from said base unit to said plurality of remote units and a reverse channel, shared by the plurality of remote units for carrying information to the base unit, wherein said forward and reverse channels include a plurality of time slots, the method comprising the steps of:

transmitting a first block of data of a data package in a first time slot on the reverse channel;

receiving the first block of data at the base unit;

transmitting a channel seizure indicator in a time slot on said forward channel;

receiving said channel seizure indicator at said remote terminal at a time that follows the transmitting of said first block by a round trip time interval;

if said seizure indicator indicates that the remote unit that transmitted said first block has successfully seized the reverse channel the remote unit transmits a plurality of additional blocks of data that constitute a remainder of said data package in a plurality of time slots of the reverse channel, wherein each given time slot includes an approximation of the number of time slots needed to transmit a remainder of the data package following said given time slot; and

detecting, at the base unit the respective approximations of the number of time slots needed to transmit the remainder of the data package that is included in the time slots on the reverse channel, and transmitting an indication of idle status along said forward channel when the detected approximation is less than a predetermined time interval.

11. The method of claim 10 wherein said predetermined time interval comprises said round trip time interval.