Peilin Hong

A temporal-credential-based mutual authentication and key agreement scheme for wireless sensor networks

Wireless sensor network (WSN) can be deployed in any unattended environment. With the new developed IoT (Internet of Things) technology, remote authorized users are allowed to access reliable sensor nodes to obtain data and even are allowed to send commands to the nodes in the WSN. Because of the resource constrained nature of sensor nodes, it is important to design a secure, effective and lightweight authentication and key agreement scheme. The gateway node (GWN) plays a crucial role in the WSN as all data transmitted to the outside network must pass through it. We propose a temporal-credential-based mutual authentication scheme among the user, GWN and the sensor node. With the help of the password-based authentication, GWN can issue a temporal credential to each user and sensor node. For a user, his/her temporal credential can be securely protected and stored openly in a smart card. For a sensor node, its temporal credential is related to its identity and must privately stored in its storage medium. Furthermore, with the help of GWN, a lightweight key agreement scheme is proposed to embed into our protocol. The protocol only needs hash and XOR computations. The results of security and performance analysis demonstrate that the proposed scheme provides relatively more security features and high security level without increasing too much overhead of communication, computation and storage. It is realistic and well adapted for resource-constrained wireless sensor networks.

Conflict Avoidance between Mobility Robustness Optimization and Mobility Load Balancing

In Long Term Evolution (LTE) networks, Mobility Robustness Optimization (MRO) and Mobility Load Balancing (MLB) are two important functions to auto-optimize the network performances. There is a close correlation between them, as they both choose adjusting handover parameters as optimization actions. The conflict may occur between the two functions when they adjust the same handover parameter in opposite directions. This can not improve the performances but waste network resources. In this paper, we present a novel scheme to solve the problem. In order to prevent the occurrence of the conflict, we set an allowed range for MLB in which the handover problems can be prevented. Analyses and simulation results demonstrate that the proposed scheme can effectively solve the conflict problem and improve the performances of both functions.

Energy-Aware Cellular Deployment Strategy Under Coverage Performance Constraints

The last ten years have witnessed explosive growth in mobile data traffic, which leads to rapid increases in energy consumption of cellular networks. One potential solution to this issue is to seek out a green deployment strategy. In this paper, we investigate the energy-efficient deployment strategy under coverage performance constraints for both homogeneous and heterogeneous cellular networks. Unlike just considering the base station (BS) density in previous work, we jointly optimize the BS density and the BS transmission power. First, we derive the relation between the average coverage probability and deployment strategy (i.e., BS density and BS transmission power) with stochastic geometry tools. Then, based on the expression results, we formulate a network energy consumption minimization framework considering coverage performance constraints and jointly determine the optimal macro BS (MaBS) density, MaBS transmission power, and micro BS (MiBS) density. With practical data sets, numerical simulation results show the following: 1) compared with homogeneous network deployment, heterogeneous network deployment has the advantage in energy efficiency performance, and 2) our joint BS density and BS transmission power optimization strategy exceeds the existing strategy, which just considers the BS density optimization in terms of energy efficiency.

Mobile-based relay selection schemes for multi-hop cellular networks

Multi-hop cellular networks (MCNs), which reduce the transmit power, mitigate the inter-cell interference, and improve the system performance, have been widely studied nowadays. The relay selection scheme is a key technique that achieves these advantages, and inappropriate relay selection causes frequent relay switchings, which deteriorates the overall performance. In this study, we analyze the conditions for relay switching in MCNs and obtain the expressions for the relay switching rate and relay activation time. Two mobile-based relay selection schemes are proposed on the basis of this analysis. These schemes select the relay node with the longest relay activation time and minimal relay switching rate through mobility prediction of the mobile node requiring relay and available relay nodes. We compare the system performances via simulation and analyze the impact of various parameters on the system performance. The results show that the two proposed schemes can obtain a lower relay switching rate and longer relay activation time when there is no reduction in the system throughput as compared with the existing schemes.

Distributed access control with adaptive privacy preserving property for wireless sensor networks

Access control plays an important role in protecting security-sensitive sensor data from being utilized by malicious users. Despite the numerous studies on access control for wireless sensor networks WSNs, however, few of them pay attention to preserving user privacy, which has recently been an urgent demand of the network users. In this paper, we propose two access control schemes with different privacy preserving properties for WSNs, which can adaptively satisfy the demands of the sensor network users. First, on the basis of our signcryption approach, we propose a distributed query protected access control scheme where the query message is encrypted in the process of user authentication. Because no other users could decrypt and read the query message, the user can preserve the privacy of the target data type. With the additional help with proxy signature, we then design a distributed anonymous access control scheme. Apart from protecting the data type information, distributed anonymous access control preserves the privacy of the users access behavior by anonymizing the users identity. In contrast to the previous privacy-preserved access control schemes for WSNs, our schemes can efficiently protect the privacy of users without significantly increasing the network overhead and the energy consumption on sensors. Copyright

RAAC: Robust and Auditable Access Control With Multiple Attribute Authorities for Public Cloud Storage

Data access control is a challenging issue in public cloud storage systems. Ciphertext-policy attribute-based encryption (CP-ABE) has been adopted as a promising technique to provide flexible, fine-grained, and secure data access control for cloud storage with honest-but-curious cloud servers. However, in the existing CP-ABE schemes, the single attribute authority must execute the time-consuming user legitimacy verification and secret key distribution, and hence, it results in a single-point performance bottleneck when a CP-ABE scheme is adopted in a large-scale cloud storage system. Users may be stuck in the waiting queue for a long period to obtain their secret keys, thereby resulting in low efficiency of the system. Although multi-authority access control schemes have been proposed, these schemes still cannot overcome the drawbacks of single-point bottleneck and low efficiency, due to the fact that each of the authorities still independently manages a disjoint attribute set. In this paper, we propose a novel heterogeneous framework to remove the problem of single-point performance bottleneck and provide a more efficient access control scheme with an auditing mechanism. Our framework employs multiple attribute authorities to share the load of user legitimacy verification. Meanwhile, in our scheme, a central authority is introduced to generate secret keys for legitimacy verified users. Unlike other multi-authority access control schemes, each of the authorities in our scheme manages the whole attribute set individually. To enhance security, we also propose an auditing mechanism to detect which attribute authority has incorrectly or maliciously performed the legitimacy verification procedure. Analysis shows that our system not only guarantees the security requirements but also makes great performance improvement on key generation.

Controller placement and flow based dynamic management problem towards SDN

The SDN architecture decouples the control plane and data plane, and multiple controllers are adopted to solve the scalability and reliability problem in SDN. However, most of the researches are focused on the control architecture and ignore the controller placement problem. Moreover, the mapping between the switches and controllers are static in current proposals, which will lead to the load unbalance of controllers under dynamic flow variations. In this paper, we define a new controller placement metric considering the node weight for a single domain at first, and then propose a dynamic switch migration algorithm to adapt to the flow dynamics and realize controller load balance in multiple SDN domains. Finally, a simple simulation platform is built to verify the proposed scheme.

Evaluating the controller capacity in software defined networking.

The flow-based OpenFlow architecture decouples the control plane and data plane, and it has involved great evolution towards traditional networks. A particular important issue in OpenFlow architecture is controller capacity, which can be defined as the number of switches a controller can manage. In this paper, we model the flow set-up requests from switches to controller as a batch arrival process Mk/M /1. Further, we analyze the controller performance with queuing theory, and derive the expression of average flow service time. Under the circumstance of a limited flow set-up time, the number of switches is determined, this provides a method to evaluate the controller capacity. Moreover, we extend the scene of a single controller to multiple controllers. All of these results are meaningful to large scale OpenFlow network deployment in the future.

Stochastic Geometry Analysis of Energy Efficiency in Heterogeneous Network with Sleep Control

Deploying Pico Base Stations (PBSs) throughout a conventional Macro Base Station (MBS) layout can improve the system capacity, which also brings substantial energy consumption. Sleep control is one of the effective ways to save energy, but it may lead to the Spectral Efficiency (SE) loss. In this letter, we study the energy-SE tradeoff in heterogeneous network with sleep control where some PBSs are adaptively switched on or off based on traffic variation. Using tools from stochastic geometry and markov chain theory, we derive the analytical expressions in terms of power consumption, SE and energy efficiency. Numerical results confirm that our theoretical analysis is reasonable. Additional, our results provide new insight into the setting of threshold of the sleep control scheme.

A Study on Reducing Chunk Scheduling Delay for Mesh-Based P2P Live Streaming

P2P streaming services have been gaining much success in recent years. In this paper, we address the design of chunk scheduling algorithm which achieves low delay for chunk distribution. We propose a distributed priority-based chunk scheduling algorithm (DPC algorithm). The proposed scheme can approach the minimum delay bound in homogeneous environment. We also extend our DPC algorithm to a general heterogeneous case where peers have different upload bandwidth. Simulation results show the priority-base chunk scheduling algorithm performs close to the theoretical bound, and suits continuity requirement of P2P streaming application.