Methods and apparatus for cellular broadcasting and communication system

• US 8,374,115 B2
• Filed: 11/21/2011
• Issued: 02/12/2013
• Est. Priority Date: 03/25/2005
• Status: Active Grant

• Current Assignee: Neo Wireless LLC (f/k/a CFIP NCF LLC) (FIG LLC (d/b/a Fortress Investment Group LLC))
• Original Assignee: Neocific Incorporated
• Inventors: Huang, Haiming, Li, Xiaodong, Lo, Titus, Li, Kemin
• Primary Examiner(s): Hu, Jinsong
• Assistant Examiner(s): Shen, Qun
• Application Number:
  US13/301,595
• Publication Number:
  US 20120063381A1
• Time in Patent Office: 449 Days
• Field of Search: 370/312, 370/335, 370/350, 370/394, 370/473, 370/474, 370/498, 370/503, 370/509
• US Class Current: 370/312
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 12/1881 with schedule organisation, e.g. priority, sequence management
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04N 21/2385 Channel allocation H04N21/266 takes precedence; Bandwidth allocation H04N21/24 takes precedence ; allocation of channels according to the instantaneous demands of the users in time-division multiplex systems H04J3/1682; admission control, resource allocation in open networks H04L12/5692; arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896; negotiating bandwidth in wireless networks H04W28/16
• CPC Class Codes: H04N 21/26208 the scheduling operation being performed under constraints
• CPC Class Codes: H04N 21/44209 Monitoring of downstream path of the transmission network originating from a server, e.g. bandwidth variations of a wireless network arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896
• CPC Class Codes: H04N 21/6131 involving transmission via a mobile phone network wireless downlink channel access H04W74/006
• 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: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/30 Resource management for broadcast services
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: H04W 92/10 between terminal device and access point, i.e. wireless air interface
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

In a cellular wireless network, methods and apparatus are disclosed for a signal broadcasting scheme that can be individually augmented for users with poor reception. The network employs a first downlink channel for broadcasting data to all mobile stations, a second downlink channel for sending signals to a specific mobile station in a cell, and an uplink channel for feeding back information to the base station. To achieve a certain user reception quality, the system adjusts its broadcasting parameters based on the statistical analysis of the feedback data. If some users still require better reception, the system individually augments their broadcast signals via the second downlink channels. Methods and apparatus are also disclosed for synchronization of data distribution by base stations, which, in part, allows the receivers to combine the receiving signals and improve their reception quality.

Claims

1. In a multi-cell communication system, a method for data communication by a base station connected to a control server via a packet data network (PDN), the base station being one of a plurality of base stations serving a plurality of mobile stations in a plurality of cells, the method comprising:

maintaining a synchronized timing of radio transmission frames with other base stations of the plurality of base stations by synchronizing to a reference common to the plurality of base stations;

receiving data distribution packets from the control server, each data distribution packet containing a synchronization protocol header with a packet sequence number and a time synchronization parameter;

decoding the packet sequence numbers and restoring the sequential order of the received distribution data packets based on the packet sequence numbers;

decoding the time synchronization parameters and determining start times for radio transmission frames based on the time synchronization parameters;

determining whether a distribution data packet has been lost or received incorrectly, and, if a distribution data packet has been lost or received incorrectly, activating an error protection mechanism to avoid interfering with transmissions by other base stations in the plurality of base stations; and

transmitting broadcast data using the same time-frequency resource as other base stations in the plurality of base stations in a single frequency network (SFN).

2. The method of claim 1, wherein a radio transmission frame comprises a plurality of subframes and each subframe contains multiple OFDM symbols.

3. The method of claim 1, wherein a length of the radio transmission frame is 10 ms.

4. The method of claim 1, wherein the reference is a global positioning system (GPS) time reference signal.

5. The method of claim 1, further comprising buffering the received distribution data packet in an electronic memory.

6. The method of claim 1, wherein the error protection mechanism is to remain silent at least for the duration of a transmission period associated with the distribution data packet that has been lost or received incorrectly.

7. A base station in a multi-cell communication system that consists of a plurality of base stations in a plurality of cells, the base station connected to a control server via a packet data network (PDN) and serving a plurality of mobile stations in a cell using a same time-frequency resource as other base stations in a single frequency network (SFN), the base station comprising:

an apparatus configured to maintain a synchronized timing of radio transmission frames with the other base stations by synchronizing to a reference common to the plurality of base stations;

a data receiving unit to receive data distribution packets from the control server, each data distribution packet containing a synchronization protocol header with a packet sequence number and a time synchronization parameter;

an apparatus configured to decode the packet sequence numbers and restore the sequential order of the received distribution data packets based on the packet sequence numbers;

an apparatus configured to decode the time synchronization parameters and determining start times for radio transmission frames based on the time synchronization parameters;

an apparatus configured to determine whether a distribution data packet has been lost or received incorrectly, and, if a distribution data packet has been lost or received incorrectly, activating an error protection mechanism to avoid interfering with transmissions by other base stations in the plurality of base stations; and

a transmitter configured to transmit broadcast data using a same time-frequency resource as other base stations in a single frequency network (SFN).

8. In a multi-cell communication system, a method for data communication by a base station connected to a control server via a packet data network (PDN), the base station being one of a plurality of base stations serving a plurality of mobile stations in the plurality of cells, the plurality of base stations having synchronized timing of radio transmission frames and capable of transmitting data using a same time-frequency resource in a single frequency network (SFN), the method comprising:

receiving a data distribution packet from the control server, wherein;

the data distribution packet comprises a synchronization protocol header and broadcast data; and

the synchronization header includes a packet sequence number and a time synchronization parameter;

buffering the received distribution data packet in an electronic memory;

recovering the packet sequence number and the time synchronization parameter from the received data distribution packet;

restoring, if needed, a sequential order of the received data distribution packet as compared with other received data distribution packets based on its packet sequence number;

deriving, based on the packet sequence number and the time synchronization parameter, a time for transmission of the broadcast data;

determining whether the distribution data packet has been received incorrectly, and, when a distribution data packet has been received incorrectly, activating an error protection mechanism to avoid interfering with transmissions by other base stations in the plurality of base stations;

scheduling the transmission of the broadcast data based on the derived time; and

transmitting the broadcast data over the single frequency network (SFN) at the derived time.