Method and apparatus for accessing a shared channel in a wireless network using a time slot allocation technique based on detecting the usage of the channel during a round trip interval

• US 6,389,474 B1
• Filed: 09/04/1998
• Issued: 05/14/2002
• Est. Priority Date: 09/04/1998
• Status: Expired due to Term

• Current Assignee: Clearwire Communications LLC (Deutsche Telekom AG), Clearwire Ip Holdings LLC (Deutsche Telekom AG)
• 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): Geckil, Mehmet B.
• Assistant Examiner(s): Prieto, Beatriz
• Application Number:
  US09/148,317
• Time in Patent Office: 1,348 Days
• Field of Search: 370/337, 370/347, 370/448, 370/466, 370/294, 380/272, 380/43, 380/260, 380/274, 375/216, 375/219, 375/298, 375/340, 709/225, 709/227, 709/231, 709/232, 709/235, 455/515, 455/512
• US Class Current: 709/232
• CPC Class Codes: H04L 47/26 using explicit feedback to the source, e.g. choke packets
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 28/14 using intermediate storage
• CPC Class Codes: H04W 74/085 collision avoidance

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 improving throughput in a wireless communication network that includes a base unit, a plurality of remote units, a reverse channel for communicating to the base unit and a forward channel for communicating from the base unit, the method comprising the steps of:

at a first remote unit, transmitting a first portion of a first data package in a time slot on the reverse channel;

during a round trip time interval, detecting whether any other remote units have successfully transmitted a time slot of data to said base unit, the round trip time interval including a plurality of time slots;

determining from said detecting step a queuing position, the queuing position decreasing in relation to the number of other remote units that successfully transmitted to the base unit before the first remote unit as detected during the round trip interval associated with the first remote unit'"'"'s said portion of first data package, for transmitting additional portions of said first data package on the reverse channel;

updating said queuing position based on information received on said forward channel; and

transmitting additional portions of said first data package in a plurality of time slots on the reverse channel when said updated queuing position indicates that the first remote unit is free to transmit.

2. The method of claim 1 comprising the further steps of:

at the base unit,

receiving a first portion of a second data package from a second remote unit prior to receiving said first portion of said first data package;

attempting to decode said received first portion of said second data package;

transmitting an indicator that said first portion of said second data package has been successfully transmitted based on receiving said first portion of said second data package and a successful decoding attempt;

receiving additional portions of said second data package from said second remote unit; and

after receiving a last time slot for said additional portions of said second data package, transmitting an indication that reflects an end of a transmission from said second remote unit.

3. The method of claim 2 wherein said step of detecting comprises the step of determining whether any time slot on said forward channel occurring after the step of transmitting said first portion and before a round trip time slot includes an indication that a time slot on said reverse channel has been successfully processed by said base unit.

4. A process for managing network resources in a wireless communication network that includes a base unit, a plurality of remote units, a reverse channel for communicating to the base unit and a forward channel for communicating to the remote units, the process comprising the steps of:

at a first remote unit,

attempting to seize control of the reverse channel by transmitting a first portion of a first data package in a time slot on the reverse channel;

after the attempt, monitoring the forward channel to detect the number of remote units that successfully transmitted a time slot of data to the base unit before the attempt, the monitoring including determining that a round trip time interval has transpired, the round trip time interval including a plurality of time slots, said number corresponding to a queuing position, the queuing position decreasing in relation to the number of other remote units that successfully transmitted to the base unit before the first remote unit as monitored during the round trip interval associated with the first remote unit transmitting said first portion of the first data package, for seizing the reverse channel; and

updating said queuing position as other remote units in the queue complete their respective transmissions to the base unit.

5. The process of claim 4, comprising the further steps of:

transmitting a plurality of time slots of data when the updated queuing position indicates that the first remote unit should seize the reverse channel.

6. A process for managing network resources in a wireless communication network that includes a base unit, a plurality of remote units, a reverse channel for communicating to the base unit and a forward channel for communicating to the remote units, the process comprising the steps of:

at the base unit, receiving a time slot of data including a first portion of a first data package on the reverse channel from a first remote unit;

transmitting, on the forward channel, a time slot of data that indicates successful receipt of said first portion of a first data package;

prior to receiving an additional portion of said first data package from said first remote unit, receiving a time slot of data on the reverse channel from a second remote unit;

transmitting, on the forward channel, a time slot of data that indicates successful receipt of the time slot of data from said second remote unit;

after receiving the time slot of data from said second remote unit, receiving a plurality of consecutive time slots on said reverse channel, said plurality of consecutive time slots containing the additional portion of said first data package from said first remote unit based on a queuing position determined by said first remote unit, the queuing position decreasing in relation to the number of other remote units that successfully transmitted to the base unit before the first remote unit as detected during a round trip interval associated with the first remote unit'"'"'s said portion of first data package, a time slot of said plurality of time slots including an end of data transmission indicator based at least in part on the round trip time interval, the round trip time interval including a plurality of time slots;

detecting the end of data transmission indicator; and

transmitting on the forward channel an indicator that reflects the detection of the end of data transmission indicator.

7. The process of claim 6 including the additional steps of:

at the second remote unit,

detecting said time slot on the forward channel that indicates successful receipt of said first portion of said first data package; and

seizing the reverse channel upon receipt of the forward channel indicator that reflects the base unit'"'"'s detection of the end of data transmission indicator.

8. A process for managing network resources in a wireless communication network that includes a base unit, a plurality of remote units, a reverse channel for communicating to the base unit and a forward channel for communicating to the remote units, the process comprising the steps of:

at a base unit receiving multiple time slots of information on the reverse channel, said multiple time slots including a plurality of attempts to seize said reverse channel from a plurality of remote units by transmitting a first portion of a first data package in a time slot on the reverse channel; and

generating time slots of information for said forward channel including information indicating whether one of said plurality of attempts were successful; and

at one remote unit of the plurality of remote units,

tracking a transmission queuing position determined by said one remote unit, the queuing position decreasing in relation to the number of other remote units that successfully seized the reverse channel to the base unit before the one remote unit as detected during the round trip interval associated with the one remote unit transmitting said first portion of the first data package, and associated with said one remote unit using the generated time slots on said forward channel, the tracking including determining that the round trip time interval has transpired, the round trip time interval including a plurality of time slots.

9. The process of claim 8 including at the base unit the further step of generating time slots of information for said forward channel indicating completion of data transmission from the respective remote units that successfully seized the reverse channel.

10. The process of claim 8 wherein said step of tracking includes the substeps of:

detecting the number of other remote units that successfully seized the reverse channel prior to said one remote unit of said plurality of remote units; and

decrementing the detected number upon detecting a time slot that indicates completion of data transmission from one of said other remote units.

11. A process for managing network resources in a wireless communication network that includes a base unit, a plurality of remote units, a reverse channel for communicating to the base unit and a forward channel for communicating to the remote units, the process comprising the steps of:

at a first remote unit,

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

after the step of transmitting, receiving a plurality of time slots on the forward

channel, the receiving including determining that a round trip time interval has transpired, the round trip time interval including a plurality of time slots;

examining a plurality of flags in each of the plurality of received time slots wherein one of said flags indicates that a reverse channel time slot was successfully received by the base unit and another one of said flags indicates that a reverse channel time slot was the last data portion of a data package from a remote unit; and

determining from the flags in said time slots on the forward channel a queuing position, the queuing position decreasing in relation to the number of other remote units that successfully transmitted to the base unit before the first remote unit as detected during the round trip interval associated with the first remote unit'"'"'s said portion of first data package, for transmitting a remainder of said data package in a plurality of consecutive time slots on the reverse channel.

12. The process of claim 11 comprising the further steps of:

at the base unit;

receiving time slots from said reverse channel;

attempting to decode data in a received time slot; and

for each successfully decoded time slot transmitting a time slot on the forward channel containing a flag that indicates that the successfully decoded time slot was successfully received.

13. The process of claim 12 comprising the further steps of:

at the base unit,

detecting when transmission of a data package from one of the remote units will be completed; and

setting said another one of said flags in a time slot on the reverse channel to indicate the detection of when the transmission of a data package from one of the remote units will be completed.

14. A process for managing network resources in a wireless communication network that includes a base unit, a plurality of remote units, a reverse channel for communicating to the base unit and a forward channel for communicating to the remote units, the process comprising:

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

after the step of transmitting, receiving a plurality of time slots on the forward channel, the receiving including determining that a round trip time interval has transpired, the round trip time interval corresponding to a plurality of time slots;

examining a plurality of indicators in each of the plurality of received time slots where in one of said indicators indicates that a reverse channel time slot was successfully received by the base unit and an other one of said indicators indicates that a reverse channel time slot was the last data portion of a data package from a remote unit; and

determining from the indicators in said time slots on the forward channel a queuing position, the queuing position decreasing in relation to the number of other remote units that successfully transmitted to the base unit before the remote unit as detected during the round trip interval associated with the first remote unit'"'"'s said portion of first data package, for transmitting a remain der of said data package in a plurality of consecutive time slots on the reverse channel.