Optimal Packet Scheduling in Tree-Structured LEO Satellite Clusters

Clusters of mobile (LEO) satellites, flying at a non-geostationary orbit, have been recently proposed, designed and made operational for achieving a global coverage of roaming users. An example of these is Teledesic. The satellites of these clusters are equipped with a radio frequency switch and connected via intersatellite links to form a specific topology. Uncoordinated packet transmission in these systems may result in collisions. Collided packets must be retransmitted, with an obvious degradation in performance, in terms of both bandwidth usage and delay. This performance degradation can be overcome by a proper scheduling of the packets. In this paper, we consider optimal (namely minimum length) packet scheduling in LEO satellite clusters. We present a preprocessing algorithm which, together with the optimal, polynomial time, packet scheduling algorithm for isolated satellites, produces an optimal schedule in tree-connected clusters. The overall algorithm inherit the time complexity of the optimal one for isolated systems, and is O(N4) for a cluster serving N roaming users.

[1]  Panayotis Antoniadis,et al.  FIRM: a class of distributed scheduling algorithms for high-speed ATM switches with multiple input queues , 2000, Proceedings IEEE INFOCOM 2000. Conference on Computer Communications. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies (Cat. No.00CH37064).

[2]  Aura Ganz,et al.  SS/TDMA scheduling for satellite clusters , 1992, IEEE Trans. Commun..

[3]  Maurizio A. Bonuccelli.  A fast time slot assignment algorithm for TDM hierarchical switching systems , 1989, IEEE Trans. Commun..

[4]  G. Bongiovanni,et al.  An Optimum Time Slot Assignment Algorithm for an SS/TDMA System with Variable Number of Transponders , 1981, IEEE Trans. Commun..

[5]  Aura Ganz,et al.  A time-wavelength assignment algorithm for a WDM star network , 1992, [Proceedings] IEEE INFOCOM '92: The Conference on Computer Communications.

[6]  Hyeong-Ah Choi,et al.  Efficient scheduling of transmissions in optical broadcast networks , 1996, TNET.

[7]  George N. Rouskas,et al.  On the design of optimal TDM schedules for broadcast WDM networks with arbitrary transceiver tuning latencies , 1996, Proceedings of IEEE INFOCOM '96. Conference on Computer Communications.

[8]  Cheng-Shang Chang,et al.  Birkhoff-von Neumann input buffered crossbar switches , 2000, Proceedings IEEE INFOCOM 2000. Conference on Computer Communications. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies (Cat. No.00CH37064).

[9]  Nick McKeown,et al.  A practical scheduling algorithm to achieve 100% throughput in input-queued switches , 1998, Proceedings. IEEE INFOCOM '98, the Conference on Computer Communications. Seventeenth Annual Joint Conference of the IEEE Computer and Communications Societies. Gateway to the 21st Century (Cat. No.98.

[10]  Miriam Di Ianni,et al.  Minimum Length Scheduling of Precedence Constrained Messages in Distributed Systems (Extended Abstract) , 1996, Euro-Par, Vol. II.

[11]  Biswanath Mukherjee,et al.  Scheduling variable-length messages in a single-hop multichannel local lightwave network , 1995, TNET.

[12]  Paul J. M. Havinga,et al.  Energy-efficient wireless networking for multimedia applications , 2001, Wirel. Commun. Mob. Comput..

[13]  Ian F. Akyildiz,et al.  A connection handover protocol for LEO satellite ATM networks , 1997, MobiCom '97.

[14]  Inder Sarat Gopal,et al.  Scheduling in Multibeam Satellites with Interfering Zones , 1983, IEEE Trans. Commun..

[15]  Maurizio A. Bonuccelli,et al.  Polynomial time optimal algorithms for time slot assignment of variable bandwidth systems , 1994, TNET.

[16]  Alan A. Bertossi,et al.  Time Slot Assignment in SS/TDMA Systems with Intersatellite Links , 1987, IEEE Trans. Commun..

[17]  Galen H. Sasaki,et al.  Scheduling transmissions in WDM broadcast-and-select networks , 1994, TNET.

[18]  Miriam Di Ianni,et al.  Complexity of Minimum Length Scheduling for Precedence Constrained Messages in Distributed Systems , 2000, IEEE Trans. Parallel Distributed Syst..

[19]  Biswanath Mukherjee,et al.  Efficient Scheduling of Nonuniform Packet Traffic in a WDM/TDM Local Lightwave Network with Arbitrary Transceiver Tuning Latencies , 1996, IEEE J. Sel. Areas Commun..

[20]  Satish Rao,et al.  Scheduling algorithms for input-queued switches: randomized techniques and experimental evaluation , 2000, Proceedings IEEE INFOCOM 2000. Conference on Computer Communications. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies (Cat. No.00CH37064).

[21]  Bezalel Gavish,et al.  LEO/MEO systems – Global mobile communication systems , 1997, Telecommun. Syst..

[22]  Chak-Kuen Wong,et al.  Incremental time-slot assignment in SS/TDMA satellite systems , 1991, IEEE Trans. Commun..

[23]  Christopher Rose.  Rapid optimal scheduling for time-multiplex switches using a cellular automaton , 1989, IEEE Trans. Commun..

[24]  B. Miller.  Satellites free the mobile phone , 1998, IEEE Spectrum.

[25]  Ravi Jain,et al.  Heuristics for Scheduling I/O Operations , 1997, IEEE Trans. Parallel Distributed Syst..

[26]  Sanjeev Khanna,et al.  Integrated scheduling of unicast and multicast traffic in an input-queued switch , 1999, IEEE INFOCOM '99. Conference on Computer Communications. Proceedings. Eighteenth Annual Joint Conference of the IEEE Computer and Communications Societies. The Future is Now (Cat. No.99CH36320).