Synchronizing push to talk service in wireless communication system

• US 7,792,540 B2
• Filed: 07/22/2005
• Issued: 09/07/2010
• Est. Priority Date: 07/28/2004
• Status: Expired due to Fees

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kwon, Oh-Ae, Lee, Se-Hee
• Primary Examiner(s): Appiah; Charles N
• Assistant Examiner(s): Karikari; Kwasi
• Application Number:
  US11/188,034
• Publication Number:
  US 20060025168A1
• Time in Patent Office: 1,873 Days
• Field of Search: 455/518, 455/519, 455/90.2, 455/434, 455/517, 455/456.1, 370/338
• US Class Current: 455/518
• CPC Class Codes: G06F 1/1626 with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• CPC Class Codes: G06F 1/1639 the display being based on projection
• CPC Class Codes: G06F 21/305 by remotely controlling device operation
• CPC Class Codes: G06F 21/6209 to a single file or object, e.g. in a secure envelope, encrypted and accessed using a key, or with access control rules appended to the object itself
• CPC Class Codes: G06F 21/74 operating in dual or compartmented mode, i.e. at least one secure mode
• CPC Class Codes: G06F 21/88 Detecting or preventing theft or loss
• CPC Class Codes: G06F 2221/2105 Dual mode as a secondary aspect
• CPC Class Codes: G06F 2221/2115 Third party
• CPC Class Codes: G11B 20/10009 Improvement or modification of read or write signals
• CPC Class Codes: G11B 20/10425 by counting out-of-lock events of a PLL
• CPC Class Codes: G11B 20/22 for reducing distortions
• CPC Class Codes: H03L 7/091 the phase or frequency detector using a sampling device H03L7/087 takes precedence
• CPC Class Codes: H04B 10/25754 Star network topology
• CPC Class Codes: H04B 7/2628 using code-division multiple access [CDMA] or spread spectrum multiple access [SSMA] H04B7/2618 takes precedence
• CPC Class Codes: H04J 13/0077 Multicode, e.g. multiple codes assigned to one user
• CPC Class Codes: H04J 13/16 Code allocation
• CPC Class Codes: H04L 1/0066 Parallel concatenated codes
• CPC Class Codes: H04L 1/0068 by puncturing
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 25/03038 with a non-recursive structure H04L25/03031 takes precedence
• CPC Class Codes: H04L 25/4902 : Pulse width modulation; Pulse position modulation
• CPC Class Codes: H04L 25/4904 : using self-synchronising codes, e.g. split-phase codes
• CPC Class Codes: H04L 25/497 : by correlative coding, e.g. partial response coding or echo modulation coding transmitters and receivers for partial response systems transversal equalizers at the transmitter end H04L25/03343
• CPC Class Codes: H04L 27/156 : with demodulation using temporal properties of the received signal, e.g. detecting pulse width
• CPC Class Codes: H04L 41/06 : Management of faults, events, alarms or notifications
• CPC Class Codes: H04L 43/0829 : Packet loss
• CPC Class Codes: H04L 47/15 : in relation to multipoint traffic arrangements for broadcast or multicast in data networks H04L12/18
• CPC Class Codes: H04L 47/70 : Admission control; Resource allocation
• CPC Class Codes: H04L 47/72 : using reservation actions during connection setup
• CPC Class Codes: H04L 47/745 : Reaction in network
• CPC Class Codes: H04L 47/765 : triggered by the end-points
• CPC Class Codes: H04L 47/822 : Collecting or measuring resource availability data
• CPC Class Codes: H04L 47/824 : Applicable to portable or mobile terminals
• CPC Class Codes: H04L 51/04 : Real-time or near real-time messaging, e.g. instant messaging [IM]
• CPC Class Codes: H04L 51/48 : Message addressing, e.g. address format or anonymous messages, aliases
• CPC Class Codes: H04L 51/58 : Message adaptation for wireless communication
• CPC Class Codes: H04L 61/2553 : Binding renewal aspects, e.g. using keep-alive messages
• CPC Class Codes: H04L 65/1016 : IP multimedia subsystem [IMS]
• CPC Class Codes: H04L 65/1043 : Gateway controllers, e.g. media gateway control protocol [MGCP] controllers
• CPC Class Codes: H04L 65/1101 : Session protocols
• CPC Class Codes: H04L 65/1104 : Session initiation protocol [SIP]
• CPC Class Codes: H04L 65/4061 : Push-to services, e.g. push-to-talk or push-to-video
• CPC Class Codes: H04L 9/085 : Secret sharing or secret splitting, e.g. threshold schemes
• CPC Class Codes: H04L 9/304 : based on error correction codes, e.g. McEliece
• CPC Class Codes: H04M 1/72415 : for remote control of appliances
• CPC Class Codes: H04M 3/42221 : Conversation recording systems at the subscriber's set H04M1/656
• CPC Class Codes: H04M 7/1295 : Details of dual tone multiple frequency signalling
• CPC Class Codes: H04N 1/00957 : Compiling jobs, e.g. for batch processing H04N1/3208 takes precedence; program code compilation G06F8/41
• CPC Class Codes: H04N 1/32106 : separate from the image data, e.g. in a different computer file
• CPC Class Codes: H04N 1/40 : Picture signal circuits H04N1/387 takes precedence
• CPC Class Codes: H04N 19/109 : among a plurality of temporal predictive coding modes
• CPC Class Codes: H04N 19/139 : Analysis of motion vectors, e.g. their magnitude, direction, variance or reliability
• CPC Class Codes: H04N 19/51 : Motion estimation or motion compensation
• CPC Class Codes: H04N 19/517 : by encoding
• CPC Class Codes: H04N 19/527 : Global motion vector estimation
• CPC Class Codes: H04N 19/625 : using discrete cosine transform [DCT]
• CPC Class Codes: H04N 19/70 : characterised by syntax aspects related to video coding, e.g. related to compression standards
• CPC Class Codes: H04N 19/91 : Entropy coding, e.g. variable length coding [VLC] or arithmetic coding
• CPC Class Codes: H04N 21/2543 : Billing , e.g. for subscription services payment schemes, architectures or protocols G06Q20/00; e-commerce G06Q30/00; arrangements for billing for the use of broadcast information or broadcast-related information H04H60/21
• CPC Class Codes: H04N 21/4181 : for conditional access
• CPC Class Codes: H04N 21/426 : Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 21/433 : Content storage operation, e.g. storage operation in response to a pause request, caching operations
• CPC Class Codes: H04N 21/4623 : Processing of entitlement messages, e.g. ECM [Entitlement Control Message] or EMM [Entitlement Management Message] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14
• CPC Class Codes: H04N 21/47211 : for requesting pay-per-view content payment schemes payment architectures or payment protocols G06Q20/00, G07F
• CPC Class Codes: H04N 21/6175 : involving transmission via Internet broadcast-related systems characterised by the transmission system being the Internet H04H60/82
• CPC Class Codes: H04N 21/6187 : involving transmission via a telephone network, e.g. POTS
• CPC Class Codes: H04N 21/6582 : Data stored in the client, e.g. viewing habits, hardware capabilities, credit card number arrangements where receivers interact with the broadcast H04H20/38
• CPC Class Codes: H04N 2201/0094 : Multifunctional device, i.e. a device capable of all of reading, reproducing, copying, facsimile transception, file transception
• CPC Class Codes: H04N 2201/3212 : of data relating to a job, e.g. communication, capture or filing of an image
• CPC Class Codes: H04N 2201/3222 : of processing required or performed, e.g. forwarding, urgent or confidential handling
• CPC Class Codes: H04N 2201/3274 : Storage or retrieval of prestored additional information
• CPC Class Codes: H04N 23/57 : Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices
• CPC Class Codes: H04N 5/38 : Transmitter circuitry for the transmission of television signals according to analogue transmission standards H04N5/14 takes precedence
• CPC Class Codes: H04N 5/4448 : for frame-grabbing
• CPC Class Codes: H04N 5/445 : for displaying additional information H04N5/50 takes precedence
• CPC Class Codes: H04N 5/45 : Picture in picture , e.g. displaying simultaneously another television channel in a region of the screen
• CPC Class Codes: H04N 5/46 : for receiving on more than one standard at will deflecting circuits of multi-standard receivers H04N3/27
• CPC Class Codes: H04N 5/64 : Constructional details of receivers, e.g. cabinets or dust covers furniture aspects of television cabinets A47B81/06
• CPC Class Codes: H04N 5/66 : Transforming electric information into light information scanning details H04N3/00
• CPC Class Codes: H04N 5/76 : Television signal recording
• CPC Class Codes: H04N 5/775 : between a recording apparatus and a television receiver
• CPC Class Codes: H04N 5/85 : on discs or drums
• CPC Class Codes: H04N 5/907 : using static stores, e.g. storage tubes or semiconductor memories H04N5/91 takes precedence
• CPC Class Codes: H04N 7/0112 : one of the standards corresponding to a cinematograph film standard
• CPC Class Codes: H04N 7/0122 : the input and the output signals having different aspect ratios
• CPC Class Codes: H04N 7/163 : by receiver means only
• CPC Class Codes: H04N 7/17327 : with deferred transmission or handling of upstream communications
• CPC Class Codes: H04N 9/3129 : scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161
• CPC Class Codes: H04N 9/642 : Multi-standard receivers
• CPC Class Codes: H04N 9/7925 : for more than one standard
• CPC Class Codes: H04N 9/8042 : involving data reduction
• CPC Class Codes: H04Q 3/0025 : Provisions for signalling
• CPC Class Codes: H04W 28/00 : Network traffic management; Network resource management
• CPC Class Codes: H04W 28/18 : Negotiating wireless communication parameters
• CPC Class Codes: H04W 28/26 : Resource reservation
• CPC Class Codes: H04W 4/10 : Push-to-Talk [PTT] or Push-On-Call services
• CPC Class Codes: H04W 4/12 : Messaging; Mailboxes; Announcements
• CPC Class Codes: H04W 4/14 : Short messaging services, e.g. short message services [SMS] or unstructured supplementary service data [USSD]
• CPC Class Codes: H04W 40/00 : Communication routing or communication path finding
• CPC Class Codes: H04W 52/30 : using constraints in the total amount of available transmission power
• CPC Class Codes: H04W 72/23 : in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 76/10 : Connection setup
• CPC Class Codes: H04W 76/12 : Setup of transport tunnels
• CPC Class Codes: H04W 76/30 : Connection release
• CPC Class Codes: H04W 76/45 : for Push-to-Talk [PTT] or Push-to-Talk over cellular [PoC] services
• CPC Class Codes: H04W 8/245 : from a network towards a terminal
• CPC Class Codes: H04W 8/26 : Network addressing or numbering for mobility support
• CPC Class Codes: H04W 84/08 : Trunked mobile radio systems
• CPC Class Codes: H04W 88/085 : Access point devices with remote components
• CPC Class Codes: H04W 88/16 : Gateway arrangements
• CPC Class Codes: Y10S 370/906 : Fiber data distribution interface, FDDI
• CPC Class Codes: Y10S 370/907 : Synchronous optical network, SONET
• CPC Class Codes: Y10S 707/99943 : Generating database or data structure, e.g. via user interface

Abstract

The present invention relates to synchronizing a terminal and a server in a shadow area of service in a push-to-talk (PTT) service system. An alive report packet is periodically transmitted to a server by a terminal having no permission to send a talk burst. A talk burst idle packet is periodically transmitted to each session-established terminal by the server in an idle state. Sessions are ended between each terminal and server if either the alive report packet or the talk burst idle packet are not received for a certain time. Accordingly, synchronization between the server and the terminal is periodically certified, unnecessary traffic generated due to inconsistent synchronization is decreased, and quality of service is enhanced.

Claims

1. A mobile terminal for synchronizing with a server in a shadow area of service in a push-to-talk (PTT) service system, the mobile terminal comprising:

means for establishing a session with the server;

means for transmitting to and receiving from the server a real time transport control protocol (RTCP) packet or a real time transport protocol (RTP) packet; and

means for ending the session established with the server if the RTCP packet is not received by the server for a specific time period, the RTCP packet being an alive report packet transmitted from a different mobile terminal that does not have permission to transmit a talk burst,

wherein the mobile terminal is synchronized with the server when in an area having no radio coverage,

wherein the synchronization between the server and the mobile terminal in the area having no radio coverage is maintained by periodic verification using the alive report packet,

wherein a period of the alive report packet is flexibly set according to a communication network to have no influence on the quality of the RTP packet, and

wherein the mobile terminal has permission to transmit the talk burst and transmits only the RTP packet to the server to maintain the quality of the RTP packet.

2. The mobile terminal of claim 1, wherein the RTP packet transmitted from the mobile terminal comprises at least one of a voice signal or a data signal.

3. The mobile terminal of claim 1, wherein a specific bit is assigned for a value of a subtype field of the RTCP packet to define the alive report packet.

4. A method for synchronizing a mobile terminal with a server in a shadow area of service in a push-to-talk (PTT) service system, the method comprising:

establishing a session with the server;

transmitting to and receiving from the server a real time transport control protocol (RTCP) packet or a real time transport protocol (RTP) packet; and

ending the session established with the server if the RTCP packet is not received by the server for a specific time period, the RTCP packet being an alive report packet transmitted from a different mobile terminal that does not have permission to transmit a talk burst,

wherein the mobile terminal is synchronized with the server when in an area having no radio coverage,

wherein the synchronization between the server and the mobile terminal in the area having no radio coverage is maintained by periodic verification using the alive report packet,

wherein a period of the alive report packet is flexibly set according to a communication network to have no influence on the quality of the RTP packet, and

wherein the mobile terminal has permission to transmit the talk burst and transmits only the RTP packet to the server to maintain the quality of the RTP packet.

5. The method of claim 4, wherein the RTP packet transmitted from the mobile terminal comprises at least one of a voice signal or a data signal.

6. The method of claim 4, wherein a specific bit is assigned for a value of a subtype field of the RTCP packet to define the alive report packet.

7. A server for synchronizing with a mobile terminal in a shadow area of service in a push-to-talk (PTT) service system, the server comprising:

means for establishing a session with the mobile terminal;

means for transmitting to and receiving from the mobile terminal a real time transport control protocol (RTCP) packet or a real time transport protocol (RTP) packet; and

means for ending the session established with the mobile terminal if the RTCP packet is not received by the server for a specific time period, the RTCP packet being an alive report packet transmitted from a different mobile terminal that does not have permission to transmit a talk burst,

wherein the mobile terminal is synchronized with the server when in an area having no radio coverage,

wherein the synchronization between the server and the mobile terminal in the area having no radio coverage is maintained by periodic verification using the alive report packet,

wherein a period of the alive report packet is flexibly set according to a communication network to have no influence on the quality of the RTP packet, and

wherein the mobile terminal has permission to transmit the talk burst and transmits only the RTP packet to the server to maintain the quality of the RTP packet.

8. The server of claim 7, wherein the server enters a talk burst idle state if the RTP packet is not received by the server for a specific time period.

9. The server of claim 7, wherein the server determines that the mobile terminal is in the shadow area of service when the RTCP packet or the RTP packet is not received for the specific time period.

10. The server of claim 7, wherein the RTP packet received by the server comprises at least one of a voice signal or a data signal.

11. A method for synchronizing a server with a mobile terminal in a shadow area of service in a push-to-talk (PTT) service system, the method comprising:

establishing a session with the mobile terminal;

transmitting to and receiving from the mobile terminal a real time transport control protocol (RTCP) packet or a real time transport protocol (RTP) packet; and

ending the session established with the mobile terminal if the RTCP packet is not received by the server for a specific time period, the RTCP packet being an alive report packet transmitted from a different mobile terminal that does not have permission to transmit a talk burst,

wherein the mobile terminal is synchronized with the server when in an area having no radio coverage,

wherein the synchronization between the server and the mobile terminal in the area having no radio coverage is maintained by periodic verification using the alive report packet,

wherein a period of the alive report packet is flexibly set according to a communication network to have no influence on the quality of the RTP packet, and

wherein the mobile terminal has permission to transmit the talk burst and transmits only the RTP packet to the server to maintain the quality of the RTP packet.

12. The method of claim 11, wherein the server enters a talk burst idle state if the RTP packet is not received by the server for the specific time period.

13. The server of claim 11, wherein the server determines that the mobile terminal is in the shadow area of service when the RTCP packet or the RTP packet is not received for the specific time period.

14. The server of claim 11, wherein the RTP packet received by the server comprises at least one of a voice signal or a data signal.

15. A method for synchronizing a server with a terminal in a shadow area of service in a push-to-talk (PTT) service system, the method comprising:

receiving a real time transport protocol (RTP) packet from a first terminal having permission to transmit a talk burst to a second terminal having no permission to transmit a talk burst to the first terminal;

receiving a real time transport control protocol (RTCP) packet from the second terminal, the RTCP packet being an alive report packet; and

ending a session with the second terminal if the alive report packet transmitted from the second terminal is not received for a specific time period,

wherein the second terminal is synchronized with the server when the second terminal is in an area having no radio coverage,

wherein the synchronization between the second terminal and the server is maintained by periodic verification using the alive report packet,

wherein a period of the alive report packet is flexibly set according to a communication network to have no influence on the quality of the RTP packet, and

wherein the first terminal transmits only the RTP packet to the server to maintain the quality of the RTP packet.

16. The method of claim 15, further comprising:

determining that the first terminal is in the shadow area of service if the RTP packet is not received for a specific time period;

releasing the permission to transmit the talk burst of the first terminal and informing the first terminal'"'"'s state to the second terminal if the first terminal is in the shadow area of service; and

ending a session with the first terminal if the first terminal is in the shadow area of service.

17. The method of claim 15, wherein a specific bit is assigned for a value of a subtype field of the RTCP packet to define the alive report packet.

18. A method for synchronizing a server with a terminal in a shadow area of service in a push-to-talk (PTT) service system, the method comprising:

transmitting a talk burst idle packet in an idle state to each session-established terminal;

receiving an alive report packet from each session-established terminal; and

ending a session with a specific terminal if the alive report packet is not received from the specific terminal for a specific time period,

wherein the specific terminal is synchronized with the server when the specific terminal is in an area having no radio coverage,

wherein the synchronization between the specific terminal and the server is maintained by periodic verification using the alive report packet,

wherein a period of the alive report packet is flexibly set according to a communication network to have no influence on the quality of the RTP packet, and

wherein a terminal other than the specific terminal has permission to transmit a talk burst and transmits only the RTP packet to the server to maintain the quality of the RTP packet.

19. The method of claim 18, further comprising ending a session with a corresponding terminal if the corresponding terminal is the only session-established terminal present after ending the session with the specific terminal.

20. The method of claim 18, wherein the talk burst idle packet and the alive report packet are respectively RTCP packets.

21. The method of claim 18, wherein a specific bit is assigned for a value of a subtype field of the RTCP packet to define the alive report packet.