Papers by Keyword: Heterogeneous Network

Abstract: The biggest challenge for heterogeneous network is co-channel interference problem, and due to the presence of interference, the system energy efficiency reduced greatly. In previous studies that use of space resources to eliminate interference between heterogeneous networks , most are based on the receiving end with a single antenna case to use zero forcing (ZF) beam-forming algorithm , however in practice the receiving end often configure multiple antennas, so this article use Block Diagonalization (BD) beam-forming algorithm to eliminate inter-cell interference after considering the coordinated multi-point transmission processing technology. This paper defines a energy efficiency metrics and convert it into a convex optimization problem by mathematical methods, and the improved energy efficiency programs is obtained ultimately.

Abstract: A dynamic sensor deployment strategy for heterogeneous mobile wireless sensor networks is proposed, so-called virtual force-directed differential evolution algorithm (VFDE). To ensure efficient coverage of networks, VFDE combines the virtual force (VF) with differential evolution algorithm (DE), where the position vector of each population is updated according to not only the historical local and global optimal solutions but also the virtual forces of sensor nodes. The key motivation of this strategy is to use the virtual force to direct the updating of DE for improving the convergence speed, and DE is used to enhance the global searching ability. Simulation results show that VFDE has better performance on regional convergence and global searching than VF algorithm and DE algorithm, and it can implement dynamic heterogeneous mobile sensor deployment efficiently and rapidly.

Abstract: An optimal heterogeneous sensor differentiated deployment schemes based on simulated annealing algorithm is proposed to solve the problems of the high density of distributing heterogeneity nodes in WSN and geographical irregularity of the sensed event. This method can not only apply to Boolean perception model of the node, but also apply to perception model. The algorithm uses the cost of sensors deployment as objective function in the context of assuring the coverage and fault tolerant of networks. The simulation results show that, the optimization method proposed in this paper can effectively convergence, under the premise to ensure network fault tolerance and robustness, reduces the cost of network deployment, improve the quality of target monitoring network.

Abstract: Femtocell is introduced to improve indoor coverage, which is beneficial for both users and operators. But it will also inevitably produce interference management issues in the heterogeneous network which consists of femtocells and macrocells. In this paper, a decentralized Q-learning-based power control strategy is proposed, comparing with homogenous power allocation and smart power control (SPC) algorithm. Simulation results have shown that Q-learning-based power control algorithm can implement the compromise of capacity between macrocells and femtocells, and greatly enhance energy efficiency of the whole network.

Abstract: Under the condition of unified communications within heterogeneous network environments, due to the presence of unified security measures such as network protocol, encryption firewalls and so on, communication within the network environments in good availability and security. As a result of the large number of business networks and significant network level in current communication network for electric system, heterogeneous network is applied in all aspects of its communication. However, in order to guarantee the availability, the safety of heterogeneous network is reduced. After studying the issues and current situation about crossing heterogeneous network, this paper makes a further research on symmetric key cryptography and asymmetric key cryptosystem, and then proposes a composite encryption algorithm based on the RSA algorithm and improved DES algorithm. Finally, the algorithm is proved to have a good security by case analysis.

Abstract: Energy efficiency is an important issue in the wireless communication system as the increasing number of wireless network users and the emerging data usage. Heterogeneous network (HetNet) is a possible way to reduce the energy consumption since the distance between user equipment (UE) and the base station is shortened in HetNet, which sharply reduce the pathloss between the transmitter and receiver. This paper investigates the energy efficiency of Pico-Macro system in terms of Joule per bit. A effects of using Cell Range Extension (CRE) of Picocell based on energy efficiency is investigated and verified through the simulation results.

Abstract: How to select a target network meeting the needs of Quality of Service (QoS) guarantee in heterogeneous network environment has become a research hotspot. In this paper, a novel differentiate weight algorithm on heterogeneous network selection is proposed. As regard of the different needs of QoS for each class of traffic in heterogeneous network, the QoS parameter weight for each class of traffic is calculated by G1 method, and then the target network is selected by technique for order preference by similarity to ideal solution (TOPSIS). At last, simulation results show that the algorithm proposed in this paper is better than average weight algorithm on selecting target network reasonably and balancing network loads.

Abstract: Energy-efficient routing is a very important issue in wireless sensor networks. An efficient routing method can avoid unnecessary data transmission and thus saves more power to extend the life of a network. The Connected Dominating Set (CDS) is a commonly used routing method which serves as a virtual backbone for a sensor network to achieve better transmission performance. The primary advantage of a CDS is its ability to adapt to the rapidly changed network topology. The construction of the CDS is a well-studied problem in an undirected unit disk graph, in which sensors are assumed to have the same transmission range. However, in practice, the sensors could have different transmission ranges due to their residual power or energy-saving mechanisms. The difference of transmission radius may form a one-way link between two nodes. Therefore, in this paper, we model the network as a directed graph and consider the CDS construction problem in such environment. We propose algorithms to construct a Strongly Connected Dominating Set (SCDS) which is a routing backbone that provides the service of efficient bidirectional data transmission between any two sensor nodes in the network.

Abstract: To achieve the goal that anybody could communicate with anyone at anytime in anyplace and in anyway, many technologies, such as GSM、CDMA、WCDMA、CDMA2000、TD-SCDMA、802.11a/b/g and so on, come true in the past years. And now, many B3G or 4G technologies are being studied. It is well-known that the future network would be heterogeneous networks. It is studied in this paper the mobility management of wireless heterogeneous network and a reversing paging process of callee is proposed which integrates paging and handoff. In the process when the caller pages the callee choosing its best suited network on one end, the callee chooses its own best network to begin a reversing paging process to set up the communication. The simulation tells that the proposed process has better performances in the call delay, the call succeeding rate and the wireless signal cost than that of the existing process in which it sets up the call first and then does vertical handoff independently.

Abstract: Nowadays, the trend for future development of the wireless communication is focused on heterogeneous network. With requirements such as E911, the positioning technology becomes widely concerned in heterogeneous network due to its added complexity compared with a simple homogeneous network. This paper discusses some typical scenarios for integration of heterogeneous network and focuses on direct mapping results to improve the final node integration accuracy; we also examine the feasibility and necessity of positioning integration based on the characteristics of heterogeneous network. This study provides for the integration of heterogeneous network positioning a theoretical framework.