Green-Markov models - new optimization strategies: a case study for user allocation in co-channel macro/femto networks

Diego L. Cardoso, Adamo L. Santana, Marcelino S. da Silva, Carlos L. R. Francês, João C. W. A. Costa, Solon V. de Carvalho, N. L. Vijaykumar


The femtocell concept aims to combine fixed-line broadband access with mobile telephony using the deployment of low-cost, low-power third and fourth generation base stations in the subscribers' homes. While the self-configuration of femtocells is a plus, it can limit the quality of service (QoS) for the users and reduce the efficiency of the network, based on outdated allocation parameters such as signal power level. To this end, this paper presents a proposal for optimized allocation of users on a co-channel macro-femto network, that enable self-configuration and public access, aiming to maximize the quality of service of applications and using more efficiently the available energy, seeking the concept of Green networking. Thus, when the user needs to connect to make a voice or a data call, the mobile phone has to decide which network to connect, using the information of number of connections, the QoS parameters (packet loss and throughput) and the signal power level of each network. For this purpose, the system is modeled as a Markov Decision Process, which is formulated to obtain an optimal policy that can be applied on the mobile phone. The policy created is flexible, allowing different analyzes, and adaptive to the specific characteristics defined by the telephone company. The results show that compared to traditional QoS approaches, the policy proposed here can improve energy efficiency by up to 10%.

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atel, "Brazil closes 2011 with record mobile telephony``, 2012. Available in: (in portuguese).

Chandrasekhar V., Andrews J. G., and Gatherer A., "Femtocell Networks: A Survey``. In IEEE Commun. Mag., vol. 46, pp. 59–67, 2008.

Ertürk M. C., Güvenc I., Arslan H., "Femtocell gateway scheduling for capacity and fairness improvement in neighboring femtocell networks``. In Proc. IEEE CogCloud Workshop (co-located with IEEE PIMRC 2010), Istanbul, Turkey, 2010.

Wang X., Athanasios V. Vasilakos, Min Chen, Yunhao Liu, Ted "Taekyoung" Kwon, "A Survey of Green Mobile Networks: Opportunities and Challenges", in ACM/Springer Mobile Networks and Applications (MONET), Vol. 17, No. 1, pp.4-20, Feb, 2012.

McLaughlin S, "Green radio: the key issues— programme objectives and overview``. Wireless World Research Forum, 2008.

SearchNetworking, Green Networking``, 2009. Available in:

Zhang Y. J., and Letaief K. B., "Multiuser adaptive subcarrier and bit allocation with adaptive cell selection for OFDM systems. In IEEE Trans. Wireless Commun., vol. 3, no. 4, pp. 1566–1575, 2004.

Rhee W. and Cioffi J. M., "Increase in capacity of multiuser OFDM system using dynamic subchannel allocation``. In Proc. IEEE Vehic. Technol. Conf. (VTC), Tokyo, Japan, pp. 1085–1089, 2000.

Kim J. Y., and Cho D. H., "A joint power and subchannel allocation scheme maximizing system capacity in dense femtocell downlink systems``. In Proc. IEEE Int. Symp. Personal, Indoor, Mobile Radio Commun. (PIMRC), Tokyo, Japan, 2009.

Chung S. P. and Lee J. C., "Performance analysis and overflowed traffic characterization in multiservice hierarchical wireless networks``. In IEEE Trans. Wireless Commun., vol. 4, no. 3, pp. 904–918, 2005.

Hu L. R. and Rappaport S., Personal communication systems using multiple hierarchical cellular overlays``. In IEEE J. Sel. Areas Commun., vol. 13, no. 2, pp. 406–415, 1995.

Liao W. H., Yen W. M., "Power-saving scheduling with a QoS guarantee in a mobile WiMAX system``. In J NetwComput Appl 32(6):1144–1152, 2009.

Han C., Beh K. C., Nicolau M., Armour S., Doufexi A., "Power efficient dynamic resource scheduling algorithms for LTE``. In Proceedings of IEEE VTC-fall, 2010.

Holger C., Lester T. W. H., and Louis G. S., "An Overview of the Femtocell Concept``. In Bell Labs Technical Journal, Vol. 13(1), pp.221246, 2008.

John D. H. and Holger C., "Deployment Options for Femtocells and Their Impact on Existing Macrocellular Networks``, In Bell Labs Technical Journal, Vol. 13(4), pp.145160, 2009.

Puterman, L. M., "Markov Decision Processes: Discrete Stochastic Dynamic Programming``. John Wiley & Sons, 1994.

Tijms, H. C., 1994. Stochastic models: an algorithmic approach. John Wiley & Sons.

Coverdale P., "Itu-T Study Group 12: Multimedia QoS requirements from a user perspective,`` Workshop on QoS and user perceived transmission quality in evolving networks, Oct, 2001.



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