Biblio

Traditional downlink (DL)-uplink (UL) coupled cell association scheme is suboptimal solution for user association as most of the users are associated to a high powered macro base station (MBS) compared to low powered small base station (SBS) in heterogeneous network. This brings challenges like multiple interference issues, imbalanced user traffic load which leads to a degraded throughput in HetNet. In this paper, we investigate DL-UL decoupled cell association scheme to address these challenges and formulate a sum-rate maximization problem in terms of admission control, cell association and power allocation for MBS only, coupled and decoupled HetNet. The formulated optimization problem falls into a class of mixed integer non linear programming (MINLP) problem which is NP-hard and requires an exhaustive search to find the optimal solution. However, computational complexity of the exhaustive search increases exponentially with the increase in number of users. Therefore, an outer approximation algorithm (OAA), with less complexity, is proposed as a solution to find near optimal solution. Extensive simulations work have been done to evaluate proposed algorithm. Results show effectiveness of proposed novel decoupled cell association scheme over traditional coupled cell association scheme in terms of users associated/attached, mitigating interference, traffic offloading to address traffic imbalances and sum-rate maximization.

Over the last few decades, accessibility scenarios have undergone a drastic change. Today the way people access information and resources is quite different from the age when internet was not evolved. The evolution of the Internet has made remarkable, epoch-making changes and has become the backbone of smart city. The vision of smart city revolves around seamless connectivity. Constant connectivity can provide uninterrupted services to users such as e-governance, e-banking, e-marketing, e-shopping, e-payment and communication through social media. And to provide uninterrupted services to such applications to citizens is our prime concern. So this paper focuses on smart handoff framework for next generation heterogeneous networks in smart cities to provide all time connectivity to anyone, anyhow and anywhere. To achieve this, three strategies have been proposed for handoff initialization phase-Mobile controlled, user controlled and network controlled handoff initialization. Each strategy considers a different set of parameters. Results show that additional parameters with RSSI and adaptive threshold and hysteresis solve ping-pong and corner effect problems in smart city.