Communication system

• US 10,362,624 B2
• Filed: 01/07/2016
• Issued: 07/23/2019
• Est. Priority Date: 01/15/2015
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Mochizuki, Mitsuru, Suzuki, Kuniyuki, Nakazawa, Masayuki, Fukui, Noriyuki, Nozawa, Haruka
• Primary Examiner(s): Zhao, Wei
• Application Number:
  US15/543,853
• Publication Number:
  US 20180007733A1
• Time in Patent Office: 1,293 Days
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 4/70 Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: H04W 48/00 Access restriction access security to prevent unauthorised access H04W12/08; Network selection; Access point selection
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 52/02 Power saving arrangements in wired systems H04L12/12; signaling of mobile application services, e.g. low battery notifications H04W4/20
• CPC Class Codes: H04W 76/19 Connection re-establishment
• CPC Class Codes: H04W 76/27 Transitions between radio resource control [RRC] states
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]
• CPC Class Codes: H04W 8/02 Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A narrow-bandwidth terminal device performs radio communication at a bandwidth narrower than a system bandwidth. The narrow-bandwidth terminal device in an idle state camps on a cell, and performs discontinuous reception of a signal transmitted from the cell. The terminal device also determines a reception condition of the signal, for example, whether the signal can be received. When it is determined that the signal cannot be received, the narrow-bandwidth terminal device moves out of a coverage area of the cell while continuing to perform the discontinuous reception. When it is determined that a discontinuous reception timer has been completed, the narrow-bandwidth terminal device continues to perform the discontinuous reception.

Claims

1. A communication system, comprising:

a communication terminal device; and

a base station device configuring at least one cell configured to perform radio communication with said communication terminal device,

wherein said communication terminal device includes a narrow-bandwidth terminal device having a narrower communication bandwidth narrower than a system bandwidth that can be used by said cell,

said narrow-bandwidth terminal device performs discontinuous reception for intermittently receiving a signal transmitted from said cell and determines a reception condition of said signal when said narrow-bandwidth terminal device is in an idle state within a coverage area of said cell, and

said narrow-bandwidth terminal device moves out of said coverage area of said cell while continuing to perform said discontinuous reception, when said reception condition of said signal satisfies a predetermined moving condition.

2. The communication system according to claim 1, wherein said moving condition is a determination that said signal cannot be received.

3. The communication system according to claim 1, wherein said moving condition is a determination that a reception quality of said signal is lower than or equal to a predetermined moving threshold.

4. The communication system according to claim 1, wherein said narrow-bandwidth terminal device performs a cell selection process upon completion of a period of said discontinuous reception after moving out of said coverage area of said cell.

5. The communication system according to claim 1, wherein said narrow-bandwidth terminal device performs a cell selection process before moving out of said coverage area of said cell, when said reception condition of said signal satisfies a predetermined moving condition.