Load balancing technique for a wireless internet access system

• US 6,980,533 B1
• Filed: 08/29/2000
• Issued: 12/27/2005
• Est. Priority Date: 04/19/2000
• Status: Expired due to Term

• Current Assignee: RPX Corporation
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Chuah, Mooi Choo, Abraham, Santosh P
• Primary Examiner(s): El-Hady, Nabil
• Assistant Examiner(s): Zhong, Chad
• Application Number:
  US09/650,058
• Time in Patent Office: 1,946 Days
• Field of Search: 711/120, 711/202, 709/232, 709/105, 709/217, 709/219, 395/650, 370/60, 370/95.1, 370/322, 370/329, 370/337, 370/347, 370/468, 725/126
• US Class Current: 370/329
• CPC Class Codes: H04W 28/10 Flow control between communication endpoints
• CPC Class Codes: H04W 72/1263 Mapping of traffic onto schedule, e.g. scheduled allocation or multiplexing of flows
• CPC Class Codes: H04W 72/535 based on resource usage policies

Abstract

In a wireless internet access system, an access point of a base station and a group of wireless modems communicate over a wireless channel. This wireless channel comprises a sequence of “dwells,” where each dwell represents a period of time, e.g., 20 milli-seconds (ms). Each dwell can convey both uplink (or upstream) and downlink (or downstream) transmissions to, and from, the group of wireless modems. However, in each dwell a particular wireless modem can only communicate half-duplex—either provide an uplink transmission to the access point, or receive a downlink transmission from the access point. The access point load balances, or distributes, the downlink transmissions to the group of wireless modems across the dwells upon detection that some dwells convey more downlink transmissions than other dwells.

Claims

1. A method for use in a transmitter, the method comprising the steps of:

using a downlink channel from the transmitter to convey information to a group of endpoint devices; and

load balancing the downlink channel;

wherein the downlink channel comprises a sequence of dwells, each dwell having a time period, and wherein the method further comprises the step of detecting that at least one dwell of the sequence conveys more downlink information than the other dwells of the sequence as a prerequisite to performing the load balancing step.

2. A method for use in a wireless system, the method comprising the steps of:

sending data from a transmitter to a group of N wireless endpoints over a downlink communications channel comprising a sequence of time slots;

detecting an imbalance such that some of the time slots convey more data than other time slots; and

shifting some of the data from at least one time slot to another time slot for reducing the detected imbalance.

3. The method of claim 2 wherein the detecting step includes the steps of:

measuring the amount of data sent in each of M timeslots to the N wireless endpoints; and

comparing the measured data for at-least-one of the M timeslots to others of the M timeslots for detecting the imbalance.

4. A method for use in a wireless system, the method comprising the steps of:

sending data to a group of N wireless endpoints from a source over a downlink communications channel comprising a sequence of time slots;

detecting an imbalance such that every other time slot of the sequence conveys more data than the remaining time slots of the sequence; and

shifting some of the data from at least one of the every other time slots to at least one of the remaining time slots for reducing the detected imbalance.

5. Apparatus for use in a communications system, the apparatus comprising:

a transmitter for providing a downlink channel to convey information to a group of endpoint devices; and

a processor for performing load balancing on the downlink channel;

wherein the downlink channel comprises a number of dwells, each dwell having a time period, and wherein the processor performs the load balancing upon detection that at least one of the dwells conveys more downlink information than the other dwells.

6. Apparatus for use in a wireless system, the apparatus comprising:

a memory for storing data for transmission from a source to a group of N wireless endpoints via a downlink channel;

a scheduler for retrieving the stored data and for measuring the amount of stored data transmitted in each of M timeslots in the downlink channel to the N wireless endpoints, and for comparing the measured data for at-least-one of the M timeslots to others of the M timeslots for detecting an imbalance in the transmission and for shifting some of the data from at least one time slot to another time slot for reducing the detected imbalance.

7. Apparatus for use in a wireless system, the apparatus comprising:

a memory for storing data for transmission to a group of N wireless endpoints;

a scheduler for retrieving the stored data and for measuring the amount of stored data transmitted in each of M timeslots to the N wireless endpoints, and for detecting an imbalance such that every other time slot of the M time slots convey more data than the remaining time slots of the M time slots; and

for shifting some of the data from at least one of the every other time slots to at least one of the remaining time slots for reducing the detected imbalance.