Time scheduling system

• US 7,304,967 B2
• Filed: 11/20/2001
• Issued: 12/04/2007
• Est. Priority Date: 11/21/2000
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Kakura, Yoshikazu
• Primary Examiner(s): Chan; Wing
• Assistant Examiner(s): SEFCHECK, GREGORY B
• Application Number:
  US09/988,595
• Publication Number:
  US 20020061000A1
• Time in Patent Office: 2,205 Days
• Field of Search: 370/336, 370/345, 370/347, 370/348, 370/337, 370/330
• US Class Current: 370/330
• CPC Class Codes: H04W 72/27 between access points
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

Time slots are allocated such that when one base station is transmitting to a terminal located in a boundary region of the respective cells of neighboring base stations, the other base stations transmit to terminals located in areas other than the boundary region, or when one on the neighboring base stations is transmitting to a terminal in a boundary region in a first sector, the other base stations transmit to terminals located in areas other than the boundary region of respective cells of those base stations in the sector opposing the first sector.

Claims

1. A cellular communication system, comprising:

a plurality of base stations that have respective communication areas with boundary regions that meet; and

plural terminals that communicate wirelessly with said base stations, each of said terminals being allocated a time slot from one of said base stations with which the respective terminal communicates;

wherein, when a first one of said terminals that communicates with a first one of said base stations using a first frequency and a second one of said terminals that communicates with a second one of said base stations using the first frequency are located in the boundary regions of said first and second ones of said base stations, said first and second ones of said base stations allocate different time slots to said first and second ones of said terminals, and

wherein, when said first one of said terminals that communicates with said first one of said base stations using the first frequency is located in the boundary regions of said first and second base stations when said second one of said terminals that communicates with said second one of said base stations using the first frequency is located out of the communication area of said first one of said base stations and out of the boundary regions of said first and second ones of said base stations, said first and second ones of said base stations are permitted to allocate a same time slot to said first and second ones of said terminals.

2. The system of claim 1, wherein said first one of said terminals has a communication quality that is equal to or below a first threshold and said second one of the terminals has a communication quality that is equal to or above a second threshold that is greater than the first threshold.

3. The system of claim 1, wherein a communication quality of said first and second ones of said terminals is divided into plural communication quality classes that are different from each other, said first one of said terminals being in a first communication quality class and said second one of the terminals being in a second communication quality class.

4. A cellular communication system, comprising:

first and second base stations that have respective communication areas with boundary regions that meet;

plural terminals that communicate wirelessly with said first and second base stations, a first one of said terminals being located in the boundary regions of said first and second base stations and a second one of said terminals being located between said second base station and the boundary region of said second base station and out of the communication area of said first base station; and

each of said first and second base stations being allocated time slots for communicating with the first and second terminals, wherein the first one of said terminals communicates with said first base station only in first time slots and communicates with said second base station only in second time slots different from the first time slots, and wherein the second one of said terminals communicates with the second base station in the first time slots,

wherein the communication areas of said first and second base stations are divided into sectors and the first one of the terminals is in the boundary region of a first one of the sectors of said first base station, and wherein the second one of said terminals is located in an area other than the boundary region of said second base station that is in a second sector of said second base station opposite the first sector of said first base station and other than the boundary region of said second base station that is in third and fourth sectors of said second base station directly adjacent to the second sector.

5. A cellular communication system, comprising:

first and second base stations that have respective communication areas with boundary regions that meet;

plural terminals that communicate wirelessly with said first and second base stations, a first one of said terminals having a communication quality that is equal to or below a first threshold and a second one of the terminals having a communication quality that is equal to or above a second threshold that is greater than the first threshold; and

each of said first and second base stations being allocated time slots for communicating with the first and second terminals, wherein the first one of said terminals communicates with said first base station only in first time slots and communicates with said second base station only in second time slots different from the first time slots, and wherein the second one of said terminals communicates with the second base station in the first time slots,

wherein the communication areas of said first and second base stations are divided into sectors and the first one of the terminals is in a first one of the sectors of said first base station, and wherein the second one of said terminals is located in an area other than a second sector of said second base station opposite the first sector of said first base station and other than third and fourth sectors of said second base station directly adjacent to the second sector.

6. A cellular communication system, comprising:

first and second base stations that have respective communication areas with boundary regions that meet;

plural terminals that communicate wirelessly with said first and second base stations, a first one of said terminals having a communication quality that is equal to or below a first threshold and a second one of the terminals having a communication quality that is equal to or above a second threshold that is greater than the first threshold; and

each of said first and second base stations being allocated time slots for communicating with the first and second terminals, wherein the first one of said terminals communicates with said first base station only in first time slots and communicates with said second base station only in second time slots different from the first time slots, and wherein the second one of said terminals communicates with the second base station in the first time slots,

wherein the communication areas of said first and second base stations are divided into sectors and the first one of the terminals is in a first one of the sectors of said first base station, and the second one of said terminals is located in a second sector of said second base station opposite the first sector of said first base station or in a third or a fourth sector of said second base station directly adjacent to the second sector, and wherein the second one of said terminals communicates with the second base station in the first time slots only when the communication quality of the second one of said terminals is equal to or above the second threshold.