Network protocol for wireless broadband-ISDN using ATM

• US 6,151,312 A
• Filed: 02/12/1996
• Issued: 11/21/2000
• Est. Priority Date: 02/12/1996
• Status: Expired due to Fees

• Current Assignee: Alcatel USA Sourcing L.P. (Nokia Corporation)
• Original Assignee: Stanford Telecommunications, Inc. (Nokia Corporation)
• Inventors: Williams, Joel, Van Blaricom, Charles, Evans, Allan, Shohara, Aki, Hunter, April
• Primary Examiner(s): NGO, RICKY QUOC
• Application Number:
  US08/600,212
• Time in Patent Office: 1,744 Days
• Field of Search: 370/321, 370/322, 370/329, 370/337, 370/338, 370/341, 370/346, 370/347, 370/348, 370/395, 370/442, 370/443, 370/449, 370/458, 370/477, 370/503, 370/469, 455/450, 455/452, 455/509
• US Class Current: 370/338
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 2012/5607 Radio
• CPC Class Codes: H04L 2012/561 Star, e.g. cross-connect, concentrator, subscriber group equipment, remote electronics
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 56/003 Arrangements to increase tolerance to errors in transmission or reception timing
• CPC Class Codes: H04W 74/02 Hybrid access

Abstract

A network protocol for the delivery of wireless broadband integrated services digital network (ISDN) using asynchronous transfer mode (ATM).

Claims

1. In a networking protocol for wireless point (base station) to multipoint users network stations where each user is stationary and which utilizes time-division multiplexing in a downstream direction of the base station to the user, and time-division multiple access in the upstream direction of the user to the base station, with the stationary users being equipped with high gain directional antennas, the improvement comprising that means for providing transmission of a convergence layer wherein:

a) time-division multiplexing is performed on an ATM cell basis in the downstream direction of the base station to the user;

b) time-division multiple access on an ATM cell basis is used in the upstream direction of the user to the base station;

c) upstream frame timing is synchronized to the downstream frame timing, where the first time slot of the downstream frame carries a Frame Start ATM cell which is an OAM cell identified by a unique reserved VPI/VCI;

d) frame periods in both the upstream and downstream directions are approximately but not greater than six milliseconds in length to allow delivery of voice traffic with minimum latency.

2. In a networking protocol for wireless point (base station) to multipoint users network stations where each user is stationary and which utilizes time-division multiplexing in a downstream direction of the base station to the user, and time-division multiple access in the upstream direction of the user to the base station, with the stationary users being equipped with high gain directional antennas, the improvement comprising that means for providing transmission of a convergence layer wherein:

a) time-division multiplexing is performed on an ATM cell basis in the downstream direction of the base station to the user;

b) time-division multiple access on an ATM cell basis is used in the upstream direction of the user to the base station;

c) upstream frame timing is synchronized to the downstream frame timing, where the first time slot of the downstream frame carries a Frame Start ATM cell which is an OAM cell identified by a unique reserved VPI/VCI;

d) frame periods in both the upstream and downstream directions are approximately but not greater than six milliseconds in length to allow delivery of voice traffic with minimum latency, and

further characterized in that means are provided for physical medium dependent layer wherein;

a) the downstream is continuous-carrier with α

=0.23 root-raised cosine filtering, with QPSK or alternately 16 QAM or 64 QAM modulation, using concatenated forward error correction coding consisting of a (243, 213, t=15) Reed-Solomon over GF (256) operating on four ATM cells and rate 7/8 convolutional code,

b) the upstream is burst-mode with α

=0.23 root raised cosine filtering, with QPSK or alternately 16 QAM modulation, using forward error correction of a (75, 53, t=11) Reed-Solomon code over GF(256).

c) time slots in the upstream direction have five preamble bytes, one ATM cell, and a one byte guard band.

3. In a networking protocol for wireless point (base station) to multipoint users station network where each user is stationary and which utilizes time-division multiplexing in a downstream direction of the base station to the user, and time-division multiple access in the upstream direction of the user to the base station, with the stationary users being equipped with high gain directional antennas, the improvement comprising that means for providing transmission of a convergence layer wherein:

a) time-division multiplexing is performed on an ATM cell basis in the downstream direction of the base station to the user;

b) time-division multiple access on an ATM cell basis is used in the upstream direction of the user to the base station;

c) upstream frame timing is synchronized to the downstream frame timing, where the first time slot of the downstream frame carries a Frame Start ATM cell which is an OAM cell identified by a unique reserved VPI/VCI;

d) frame periods in both the upstream and downstream directions are approximately but not greater than six milliseconds in length to allow delivery of voice traffic with minimum latency, and

further characterized by means for medium access control functions being provided through;

a) in-band signaling through ATM cells with reserved VPI/VCIs so that the requirements for acquisition, demodulation, and forward error correction are uniform across the data, control, and management planes of the network protocol;

b) transmission convergence layer medium access control which dynamically assigns the time slots in the upstream direction to accommodate varying demands for bandwidth by multiple users;

c) contiguous time slots at the beginning of the upstream frame are used for entry into the network by users whose two-way range timing has not been resolved to avoid mutual interference, where users entering the network remain on net entry time slots until their timing is aligned;

d) session requests are performed on a contention basis through contention time slots;

e) carrying control plane acknowledgment of service requests in the payload of the frame start ATM cell in the downstream frame.

4. In a networking protocol for wireless point (base station) to multipoint users network stations where each user is stationary and which utilizes time-division multiplexing in a downstream direction of the base station to the user, and time-division multiple access in the upstream direction of the user to the base station, with the stationary users being equipped with high gain directional antennas, the improvement comprising that means for providing transmission of a convergence layer wherein:

a) time-division multiplexing is performed on an ATM cell basis in the downstream didrection of the base station to the user;

b) time-division multiple access on an ATM cell basis is used in the upstream direction of the user to the base

c) upstream frame timing is synchronized to the downstream frame timing, where the first time slot of the downstream frame carries a Frame Start ATM cell which is an OAM cell identified by a unique reserved VPI/VCI;

d) frame periods in both the upstream and downstream directions are approximately but not greater than six milliseconds in length to allow delivery of voice traffic with minimum latency, and

further characterized in that means are provided for management plane functions through;

a) in-band signaling through ATM cells with reserved VPI/VCIs so that the requirements for acquisition, demodulation, and forward error correction are uniform across data, control, and management planes of the network protocol;

b) polling users by the base station, with uses responding on dedicated time slots in an upstream frame;

c) carrying management plane polling requests in the payload of the frame start ATM cell in an downstream frame carries,

d) upstream time slot synchronization is maintained to within ±

2 modulation symbols through timing control from the base station to the user and through slaving the user transmit symbol clock to its received symbol clock in the transmission convergence layer,

e) upstream poser control is employed to ensure adequate received signal strength at the base station while minimizing adjacent cell interference.

5. In a networking protocol for wireless point base station to multipoint users network stations where the base station has a central processing unit each user is stationary and which utilizes time-division multiplexing in a downstream directon of the base station to the user, and time-division multiple access in the upstream direction of the user to the base station, with the stationary users being equipped with high gain directional antennas, the improvement comprising that means for providing transmission of a convergence layer wherein:

a) time-division multiplexing is performed on an ATM cel basis in the downstream direction of the base station to the user;

b) time-division multiple access on an ATM cell basis is used in the upstream direction of the user to the base station;

c) upstream fram timing is synchronized to downstream frame timing, where the first time slot of downstream frames carries a Frame Start ATM cell which is an OAM cell identified by a unique reserved VPI/VCI;

d) frame periods in both the upstream and downstream directions are approximately but not greater than six milliseconds in length to allow delivery of voice traffic with minimum latency, and

further characterized in each said base station including;

a) means for routing of in-band signaling ATM cells by an ATM switching device to and from the central processing unit;

b) means for measuring timing offsets by subscribers through counting periods of the referenced symbol clock from a master frame epoch to the detection of a Barker sequence of a received transmission from the user;

c) means for measuring received signal level via bit error rate estimation for closed loop power control of a user transmitter.

6. In a networking protocol for wireless point (base station) to multipoint users network stations where each user is stationary and which utilizes time-division multiplexing in a downstream direction of the base station to the user, and time-division multiple access in the upstream direction of the user to the base station, with the stationary users being equipped with high gain directional antennas, the improvement comprising that means for providing transmission of a convergence layer wherein:

a) time-division multiplexing is performed on an ATM cell basis in the downstream direction of the base station to the user;

b) time-division multiple access on an ATM cell basis is used in the upstream direction of the user to the base station;

c) upstream frame timing is synchronized to downstream frame timing, where the first time slot of a downstream frame carries a Frame Start ATM cell which is an OAM cell identified by a unique reserved VPI/VCI;

d) frame periods in both the upstream and downstream directions are approximately but not greater than six milliseconds in length to allow delivery of voice traffic with minimum latency, and

further characterized in that each user equipment includes;

a) means for routing in-band signaling ATM cells to and from an ATM switching or segmentation and reassembly device to the user equipment central processing unit;

b) means for adjusting transmitter power based on received power level and power control commands via in-band signaling ATM cells from the base station;

c) means for slaving a transmit symbol clock reference to the received symbol clock reference;

d) means for adjusting the transmit symbol clock timing to minimize interference to other users.

7. In a networking protocol for wireless point base station to multipoint users network stations where each user is stationary and which utilizes time-division multiplexing in a downstream direction of the base station to the user, and time-division multiple access in the upstream direction of the user to the base station, with each stationary user being equipped with high gain directional antennas, the improvement comprising that means for providing transmission of a convergence layer wherein:

a) time-division multiplexing is performed on an ATM cell basis in the downstream direction of the base station to the user;

b) time-division multiple access on an ATM cell basis is used in the upstream direction of the user to the base station;

c) upstream frame timing is synchronized to the downstream frame timing, where the first time slot of the downstream frame carries a Frame Start ATM cell which is an OAM cell identified by a unique reserved VPI/VCI;

d) frame periods in both the upstream and downstream directions are approximately but not greater than six milliseconds in length to allow delivery of voice traffic with minimum latency, and

further characterized in having means for providing local area network functionality through a proxy local area network emulation client residing in the base station which performs signaling and address resolution for the users network station.