Transmission of data over a radio frequency channel

• US 6,564,071 B1
• Filed: 06/26/1998
• Issued: 05/13/2003
• Est. Priority Date: 01/13/1992
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Microcom Systems Incorporated
• Inventors: Carey, Richard, Kloc, Dennis, Greene, Roy, Falk, Jerry, Bergins, Lewis A., Onorato, Michael
• Primary Examiner(s): VO, NGUYEN THANH
• Application Number:
  US09/105,509
• Time in Patent Office: 1,782 Days
• Field of Search: 455/422, 455/67.1, 455/67.3, 455/557, 455/553, 455/434, 455/450, 455/62, 455/550, 455/556, 455/575, 455/126, 455/95, 455/69, 714/746, 714/749, 714/748
• US Class Current: 455/557
• CPC Class Codes: H04B 1/1027 assessing signal quality or detecting noise/interference for the received signal
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 1/188 Time-out mechanisms
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04M 15/00 Arrangements for metering, time-control or time indication ; Metering, charging or billing arrangements for voice wireline or wireless communications, e.g. VoIP
• CPC Class Codes: H04M 2215/14 Billing aspects relating to the actual charge
• CPC Class Codes: H04M 2215/143 Non communication time, i.e. billing the user for the actual time used by the service, not for the time awaiting responses due to network problems; Billing the user when there is a satisfied QoS
• CPC Class Codes: H04M 2215/146 Data billing, e.g. wherein the user is charged based only on the time he receives data
• CPC Class Codes: H04M 2215/32 Involving wireless systems
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/14 using intermediate storage
• CPC Class Codes: H04W 4/24 Accounting or billing
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 76/30 Connection release
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 99/00 Subject matter not provided for in other groups of this subclass

Abstract

An improved system for the transmission of data over a cellular telephone channel is provided. The system is especially adapted to reduce the cost associated with cellular telephone calls by allowing data transmission only when the channel signal level is greater than a pre-defined value, so as maximize the probability that a transmission will be successful. In addition, the system provides for user transparent reconnection and reestablishment of a dropped link, allowing transmission to continue where dropped without the need to retransmit data already successfully received. As an additional benefit, the system provides a mechanism for call timing and billing so that an estimated bill may be generated based on connection time.

Claims

1. A data communication system for transferring data over a communications channel between a local system and a remote system, said data communications system comprising:

a DTE interface connecting said data communications system to said local system so as to permit data to be transferred between said data communication system and said local system;

an analog interface connecting said data communications system to said communications channel; and

a protocol and control processor connected so as to enabled the local system to transfer data between said analog interface and said DTE interface, and transmit and receive data over said communications channel according to a predefined data communication protocol, whereby data is transferred in packets;

said protocol and control processor including credits determined as a function of a buffer size available at said remote system for receiving packets, and

wherein said protocol and control processor is adapted to enable the local system to repeat the transmission of all packets which have not been acknowledged if said credits indicate that new packets cannot be sent to said remote system.

2. A data communication system according to claim 1, wherein said remote system includes a receive buffer having a limited size buffer memory and said protocol and control processor enables the local system to transmit and receive data over said communications channel according to a predefined data communication protocol,

whereby said protocol and control processor enables the local system to transmit new packets to the remote system if said credits indicate that new packets can be sent to the remote system.

3. A data communication system according to claim 2, wherein said protocol and control processor only enables the local system to send new packets to the remote system if said credits indicate that new packets can be sent to the remote system.

4. A data communication system according to claim 1 wherein said data communication protocol is an error correcting protocol.

5. A data communication system according to claim 1 wherein said data communication protocol is a protocol for the transmission of data over a telephone network and said communications channel includes a telephone network.

6. A data communications apparatus adapted for transferring data over a communication channel between a local system and a remote system, said data communications apparatus comprising:

a DTE interface adapted for connecting said data communications apparatus to said local system so as to permit data to be transmitted to and received from said local system;

an analog interface adapted for connecting said data communications apparatus to said communication channel and;

a protocol and control processor adapted for enabling the local system to transfer data between said analog interface and said DTE interface, and to transmit and receive data over said communications channel according to a predefined data communication protocol, whereby data is transferred in packets;

said protocol and control processor including credits determined as a function of a buffer size available at said remote system for receiving packets,

wherein said protocol and control processor is adapted to enable the local system to repeat the transmission of all packets which have not been acknowledged if said credits indicate that new packets cannot be sent to said remote system.

7. A data communication apparatus according to claim 6, wherein said remote system includes a receive buffer having a limited size buffer memory adapted for storing data, and said protocol and control processor enables the local system to transmit and receive data over said communications channel according to a predefined data communication protocol whereby said protocol and control processor enables the local system to transmit new packets to the remote system if said credits indicate that new packets can be sent to the remote system.

8. A data communication apparatus according to claim 7, wherein said protocol and control processor only enables the local system to send new packets to the remote system if said credits indicate that new packets can be sent to the remote system.

9. A data communication system according to claim 6 wherein said data communication protocol is an error correcting protocol.

10. A data communication system according to claim 6 wherein said data communication protocol is a protocol for the transmission of data over a telephone network and said communications channel includes a telephone network.

11. A method of transmitting data over a data communications channel from a local system to a remote system, comprising the steps of:

transmitting at least one data packet over said communications channel to said remote system;

repeatedly transmitting said at least one data packet over said communications channel to said remote system until an acknowledgement for said data packet is received from said remote system or said communications channel becomes disconnected;

providing credits and determining said credits as a function of a buffer size available at said remote system to receive packets; and

repeating the transmission of all packets which have not been acknowledged if said credits indicate that new packets cannot be sent to said remote system.

12. A method of transmitting data over a data communications channel from a local system to a remote system whereby said remote system includes a receive buffer memory having a predetermined size, said method further comprising the steps of:

providing credits and determining said credits as a function of said receive buffer memory available to receive data packets at said remote system;

determining a quantity of data packets that can be transmitted to said remote system;

transmitting said quantity of data packets to said remote system; and

repeatedly transmitting all of said data packets until an (a) acknowledgment from said remote system that said data packets have been received or (b) said communications channel becomes disconnected if said credits indicate that new packets cannot be sent to said remote system.