CS 68191 Masters Seminar / CS 89191 Doctoral Seminar
Spring 2007



Doctoral Student Presentation

A Critical Design Evaluation for Two Space Routing Protocols

Omar Y. Tahboub



During the last decade, the space industry has achieved a significant growth in providing various commercial space applications such as interplanetary communication, space tourism and entertainment. Recently, there has been an increasing demand for space communication infrastructures integrated with open-standard space Internet to satisfy the current and future commercial space applications. Currently, space protocol architectures are based on custom industrial specific standards. However, these protocol architectures along with terrestrial Internet standards are inadequate due to the oddities of the space environments [1]. The next generation space protocol architectures aim to provide standard and efficient (layered) protocol design for space network infrastructures that includes: proximity, inter-spacecraft, and interplanetary networks [1][2].

One essential service of the next generation space protocols is packet routing by which network protocol layer provides. Inter-spacecraft networks have three main characteristics: (1) constant node mobility, (2) link intermittency, and (3) high network topology dynamicity as a result of first two characteristics. From the given characteristics, it has to be noted that router in space networks are mobile, and thus it is pretty difficult of near impossible to establish an end-to-end route between a source and destination spacecrafts prior to data transmission. Therefore, the characteristics of inter-spacecraft networks are considered design challenges space network routing protocols are required to address. The absence of end-to-end route between communicating peers makes conventional proactive mobile routing protocols like DSDV [3] and reactive protocol like AODV [4] inapplicable. For proactive protocols, it is assumed that routers are static, whereas routers in space are mobile. For the reactive protocols communication links age rapidly due to link intermittency, and hence disallowing route establishment to occur effectively.

In this paper, we provide a critical design evaluation for two recently proposed space routing protocols: Positional Link State (PLS) [5] and Interrogation-Based Relay Routing (IBRR) [6][7] in terms of the approaches they provide for solving the space network layer design challenges posed by the next generation protocol architectures. In addition, we first provided a detailed description for the network architecture on which these routing protocols operate. Second, we described each routing protocol in terms of its purpose and routing mechanisms it provides for space networks. Finally, based on the description given for each routing protocol, we critically evaluate them in terms of the approaches they provide to the space network layer design challenges.

References

[1] Tahboub, O. Y, Khan, J. I., "A Critical Design Evaluation of the Next Generation Space Network Protocols Architectures", unpublished manuscript, 2006.

[2] Bhasin, K., and Hayden, J. L., "Space Internet Architectures and Technologies for NASA Enterprises," Int. J. Satell. Commun. 2002; 20, 311-332.

[3] C.E Perk ins, P. B hagwat, "H ighly D ynamic D estination- Sequenced Distance-Vector Routing (DSDV) for Mobile Computers," in Proc. of ACMSIGCOMM,1994.

[4] C. Perkins. "Ad Hoc On Demand Distance Vector (AODV) Routing" IETF, Internet Draft, draft-ietf-manet-aodv-00.txt, November 1997.

[5] Gnawali O., Polyakov M., Bose p., and Govindan R., "Data Centric, Position-Based Routing In Space Networks", Proceedings of the 26th IEEE Aerospace Conference, March 2005.

[6] Shen C-C, Rajagopalan S.,Borkar G.,and Jaikaeo C., "A flexible routing architecture for ad hoc space networks", Computer Networks: The International Journal of Computer and Telecommunications Networking, Volume 46 , Issue 3 (October 2004), Special issue: Networking for the earth science, Pages: 389 - 410,2004.

[7] Shen C-C,Borkar G.,Rajagopalan S., and Jaikaeo C.,"Interrogation-Based Relay Routing for Ad hoc Satellite Networks", Global Telecommunications Conference GLOBECOM '02, Volume: 3, On page(s): 2920- 2924 vol.3, 2002.