24,062 research outputs found
Efficient Proactive Caching for Supporting Seamless Mobility
We present a distributed proactive caching approach that exploits user
mobility information to decide where to proactively cache data to support
seamless mobility, while efficiently utilizing cache storage using a congestion
pricing scheme. The proposed approach is applicable to the case where objects
have different sizes and to a two-level cache hierarchy, for both of which the
proactive caching problem is hard. Additionally, our modeling framework
considers the case where the delay is independent of the requested data object
size and the case where the delay is a function of the object size. Our
evaluation results show how various system parameters influence the delay gains
of the proposed approach, which achieves robust and good performance relative
to an oracle and an optimal scheme for a flat cache structure.Comment: 10 pages, 9 figure
On the Two-user Multi-carrier Joint Channel Selection and Power Control Game
In this paper, we propose a hierarchical game approach to model the energy
efficiency maximization problem where transmitters individually choose their
channel assignment and power control. We conduct a thorough analysis of the
existence, uniqueness and characterization of the Stackelberg equilibrium.
Interestingly, we formally show that a spectrum orthogonalization naturally
occurs when users decide sequentially about their transmitting carriers and
powers, delivering a binary channel assignment. Both analytical and simulation
results are provided for assessing and improving the performances in terms of
energy efficiency and spectrum utilization between the simultaneous-move game
(with synchronous decision makers), the social welfare (in a centralized
manner) and the proposed Stackelberg (hierarchical) game. For the first time,
we provide tight closed-form bounds on the spectral efficiency of such a model,
including correlation across carriers and users. We show that the spectrum
orthogonalization capability induced by the proposed hierarchical game model
enables the wireless network to achieve the spectral efficiency improvement
while still enjoying a high energy efficiency.Comment: 31 pages, 13 figures, accepted in IEEE Transactions on Communication
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