Skip to main content
SpringerLink
Log in

Uplink relaying in hybrid wireless networks with out-of-cell interference reduction

  • Published:
Wireless Networks Aims and scope Submit manuscript

Abstract

The next generation broadband access networks must provide high speed bidirectional data channels and support more concurrent subscribers than ever before. While mega-bits-per-second data rates have been demonstrated for the downlink channels, progress on uplink has been slow. We propose a hybrid architecture for CDMA uplink that seamlessly integrates short-range radio and WCDMA interfaces in the same network. In our scheme, mobile stations (subscribers) can operate as Relaying Mobile Terminal (RMT) to relay uplink traffic for nearby mobile stations. Our analysis and simulations show that the deployment of RMTs significantly reduces the radio transmissions in the CDMA uplink. Moreover, the scheme results in a much lower out-of-cell interference to the neighboring network cells. The problem of finding the optimum RMT set turns out to be NP-hard. Several heuristics are evaluated in terms of RMT size and out-of-cell interference. In particular, we investigated a novel vertex cover based heuristic algorithm. Our method uses mobile pilot signals and mobile location to estimate a interference function for each node. This function is then used in selecting a maximum matching for the candidate RMT set. Simulation results are somewhat surprising: the simple greedy algorithm has very close performance to that of the optimum algorithm when only the RMT size is concerned. When out-of-cell interference is considered, the proposed algorithm outperforms both greedy and 2-approximation algorithm.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10

Similar content being viewed by others

Notes

  1. Typical cell radius in a 3G network is 2 miles, which is about 30 times of the 100-m effective range for a typical WLAN.

  2. The pilot channel is transmitted in low power, and uses only a small portion of a slot time to minimize the interference.

  3. Total number of mobiles in the 120°-fan area of the cell sector.

  4. In fact, ln(|V|) is a tight upper bound.

References

  1. Aggelou, G. N., & Tafazolli, R. (2001). On the relaying capacity of next-generation GSM cellular networks. IEEE Personal Communications Magazine, 8(1), 40–47.

    Article  Google Scholar 

  2. Bar-Yehuda, R., & Even, S. (1985). A local ratio theorem for approximating the weighted vertex cover problem. Annals of Discrete Mathematics, 25, 27–45.

    MathSciNet  Google Scholar 

  3. Chvatal, V. (1979). A greedy heuristic for the set covering problem. Mathematics of Operations Research, 4, 233–235.

    Article  MATH  MathSciNet  Google Scholar 

  4. Cormen, T., Leiserson, C., & Rivest, R. (1990). Introduction to algorithms. Cambridge MA: MIT Press.

    MATH  Google Scholar 

  5. Dai, F., & Wu, J. (2004). An extended localized algorithm for connected dominating set formation in ad hoc wireless networks. IEEE Transactions on Parallel and Distributed Systems, 15(10), 908–920.

    Article  Google Scholar 

  6. Guha, S., & Khuller, S. (1998). Approximation algorithms for connected dominating sets. Algorithmica, 20(4), 374–387.

    Article  MATH  MathSciNet  Google Scholar 

  7. Luo, H., Ramjee, R., Sinha, P., Li, L., & Lu, S. (2003). UCAN: A unified cellular and ad-hoc network architecture. In Proceedings of ACM Mobicom’03. Sep 2003.

  8. Marathe, M. V., Breu, H., Hunt, H. B. III, Ravi, S. S., & Rosenkrantz, D. J. (1995). Simple heuristics for unit disk graphs. Networks, 25, 59–68.

    Article  MATH  MathSciNet  Google Scholar 

  9. Nemhauser, G. L., & Trotter, L. E. (1975). Vertex packings: Structural properties and algorithms. Mathematical Programming, 8, 232–248.

    Article  MATH  MathSciNet  Google Scholar 

  10. Paschos, V. T. (1997). A survey of approximately optimal solutions to some covering and packing problems. ACM Computing Surveys, 29(2), 171–209.

    Article  Google Scholar 

  11. Qayyum, A., Viennot, L., & Laouiti, A. (2002). Multipoint relaying for flooding broadcast messages in mobile wireless networks. In Proceedings of the Hawaii International Conference on System Sciences (HICSS’02). January 2002.

  12. Viterbi, A. J., Viterbi, A. M., et al. (1994). Soft Handoff extends CDMA cell coverage and increases reverse link capacity. IEEE Journal on Selected Areas in Communications, 12, 1281–1288.

    Article  Google Scholar 

  13. Wu, H., Qiao, C., De, S., & Tonguz, O. (2001). An integrated cellular and ad hoc relaying system: iCAR. IEEE Journal on Selected Areas in Communications, 19(10), 2105–2115.

    Article  Google Scholar 

  14. Wu, J. (2002). Extended dominating-set-based routing in ad hoc wireless networks with unidirectional links. IEEE Transactions on Parallel and Distributed Systems, 13(9), 866–881.

    Article  Google Scholar 

  15. Wu, X., Chan, S.-H., & Mukherjee, B. (2000). MADF: A novel approach to add an ad-hoc overlay on a fixed cellular infrastructure. In Proceedings of IEEE WCNC (Vol. 2, pp. 549–554).

Download references

Author information

Authors and Affiliations

  1. Virginia Commonwealth University, Richmond, USA

    Ju Wang

  2. University of Florida, Gainesville, USA

    Jonathan C. L. Liu

Authors
  1. Ju Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Jonathan C. L. Liu
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Ju Wang.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Wang, J., Liu, J.C.L. Uplink relaying in hybrid wireless networks with out-of-cell interference reduction. Wireless Netw 15, 1113–1125 (2009). https://doi.org/10.1007/s11276-008-0106-5

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11276-008-0106-5

Keywords

Search

Navigation