Data communication method and mobile communication system

• US 9,930,639 B2
• Filed: 08/24/2016
• Issued: 03/27/2018
• Est. Priority Date: 09/26/2006
• Status: Active Grant

• Current Assignee: TCL Communication Technology Holdings Ltd. (TCL Technology Group Corp.)
• Original Assignee: TCL Communication Technology Holdings Ltd. (TCL Technology Group Corp.)
• Inventors: Mochizuki, Mitsuru, Maeda, Miho, Iwane, Yasushi, Fukui, Noriyuki, Mishuku, Tetsuya, Takano, Michiaki, Fujie, Ryoichi, Tani, Shigenori, Okubo, Akira, Ozaki, Keisuke
• Primary Examiner(s): LY, ANH VU H
• Application Number:
  US15/246,304
• Publication Number:
  US 20170048819A1
• Time in Patent Office: 580 Days
• Field of Search: None
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 24/04 Arrangements for maintaining operational condition
• CPC Class Codes: H04W 36/0007 for multicast or broadcast services, e.g. MBMS multicast or broadcast application services H04W4/06; resource management for broadcast services H04W72/30; connection management for selective distribution or broadcast H04W76/40
• CPC Class Codes: H04W 36/0072 of resource information of target access point
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling
• CPC Class Codes: H04W 72/30 Resource management for broadcast services
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

Since OFDM (Orthogonal Frequency Division Multiplexing), which is a downlink access scheme used for an LTE (Long Term Evolution) communication system, is weak at interference, it is preferable that the number of base stations for transmitting the same E-MBMS (Evolved Multimedia Broadcast Multicast Service) data base not excessive.

Thus, the mobile terminal performs: processing of obtaining measurement quality values by measuring reception quality of each base station; processing of deciding on whether the measurement quality value of a serving base station exceeds a certain receiving level; processing of adding measurement quality values of other base stations to the measurement quality value of the serving base station until the sum exceeds the certain receiving level; and processing of notifying the serving base station of the serving base station and other base stations as candidates for an active set for E-MBMS. This makes it possible to select as the active set for E-MBMS an appropriate number of base stations that make it compatible to maintain good reception quality and to prevent interference.

Claims

1. A mobile communication system that transmits Evolved Multimedia Broadcast Multicast Service (E-MBMS) data, comprising:

a mobile terminal, which requests entry into E-MBMS service;

a serving base station which receives a request by the mobile terminal for entry into the E-MBMS service, and transmits a signal to the mobile terminal for measuring a first E-MBMS signal quality, wherein the signal is carried over a transport channel and is received independently from an E-MBMS data; and

a plurality of additional base stations requested by the mobile terminal to be included in an active set of base stations transmitting E-MBMS data to the mobile terminal, wherein one of the plurality of additional base stations transmits a second signal to the mobile terminal for measuring a second E-MBMS signal quality;

wherein one of the plurality of additional base stations is selected as a member of the active set of base stations based on determining whether a sum of the first E-MBMS signal equality measurement associated with the serving base station and the second E-MBMS signal quality measurement associated with the one of the plurality of additional base stations exceeds a signal quality threshold that varies according to a degree of congestion of a serving base station scheduler; and

wherein the mobile terminal transmits a request to drop any excess base stations from the active set if the first E-MBMS signal quality measurement associated with the serving base station exceeds the signal quality threshold.

2. A mobile communication system that transmits Evolved Multimedia Broadcast Multicast Service (E-MBMS) data, comprising:

a mobile terminal, said mobile terminal which requests entry into E-MBMS service;

a serving base station which receives the request, and transmits a signal to the mobile terminal for measuring E-MBMS signal quality, wherein the signal is carried over a logic channel and is received independently from an E-MBMS data; and

a plurality of additional base stations that are requested by the serving base station to be included in an active set of base stations transmitting E-MBMS data to the mobile terminal,

wherein candidate base stations are selected into the active set of base stations based on a degree of congestion for each of the candidate base stations and based on determining whether a sum of the E-MBMA signal received from the serving base station and the E-MBMS data received from one of the plurality of additional base stations exceeds a signal quality threshold that varies according to a degree of congestion of a serving base station scheduler; and

wherein the active set of base stations is every neighboring base station of the serving base station.