Pre-Authentication Schemes for UMTS-WLAN Interworking

The purpose of this paper is to demonstrate a reliable construction of wireless local area network (WLAN) and universal mobile telecommunications systems (UMTS) interoperating system. The proposed system shall provide high data rates alongside a significant coverage area. It is known that WLAN makes available high data rates within a very restricted coverage. On the other hand UMTS provides comparatively extended coverage with low data rates. Prior papers planned to integrate WLAN with UMTS to get the best of both systems. Accordingly several types of integration solutions have been evaluated upon success of integration between the 3G and the IEEE 802.11a systems. This approach is especially pragmatic in shadow of the fact that the evolved UMTS system fielding had been delayed due to economic factors. To accomplish an inclusive handover between both technologies this work made use of session initiation protocol (SIP) as signaling protocol and the mobile IP which is the standard communications protocol to allow mobile device users to move from one network to another as a handover protocol. This approach is shown to be useful given that no major alterations in the node Bs are required. Conceptual and practical comparisons showed that the use of mobile stream control transmission protocol (mSCTP) as transport layer protocol is considered the best approach for achieving interoperability between UMTS and WLAN. On the physical layer MPLS has been used to achieve load balancing and protection from congestions. We deployed different integration solutions for ensuring service continuity across different radio technologies that provide high-quality of service. Performance tests for different application traffic types and distributions have been conducted for both HTTP and multimedia streaming.

최근 Universal Mobile Telecommunication System (UMTS)와 Wireless Local Area Network (WLAN)의 장점을 효율적으로 사용하기 위한, 두 네트워크의 인터워킹 구조에 대한 연구가 활발히 진행되고 있다. 하지만 UMTS와 WLAN은 그 전송량의 차이가 커서, 전송 품질이 저하되기 쉽다. 그러므로 본 논문에서는 tight coupling을 기반으로 이동성 예측 기법을 이용한 동적인 서비스 품질 (QoS: Quality of Service)을 보장해주기 위한 두 네트워크 간 인터워킹 구조를 제안한다. 또한, 이렇게 제안한 인터워킹 구조를 ns-2로 시뮬레이션 하였으며, 그 결과 제안하는 인터워킹 구조가 기존의 인터워킹 구조에 비해 핸드오프 손실률을 줄이고, 핸드오프 순간 QoS를 제공해주지 않는 방법보다 훨씬 더 많은 양의 패킷을 전송한다는 것을 알 수 있다. Universal Mobile Telecommunications System (UMTS) and Wireless Local Area Network (WLAN) have been developed independently. Then, many researchers have studied UMTS-WLAN interworking architecture for the efficiency. However, the transmission capacity difference of two networks causes the transmission quality degradation. Therefore, this paper proposes a UMTS-WLAN interworking architecture for Quality of Service (QoS). The proposed architecture is based on tight coupling and dynamically guarantees QoS by the mobility prediction method. The proposed architecture is simulated by ns-2. Performance experimental results show that the proposed architecture reduces the handover dropping probability comparing with the existing method and enhances the amount of receiving packets comparing with the method without guaranteeing QoS.

With the rapid development of wireless local area network (WLAN) and the proliferation of intelligent terminals, the current WLAN protocol is no longer able to meet the needs of users. Therefore, the next generation WLAN: IEEE 802.11ax has emerged to meet the growing demand for user traffic. Orthogonal Frequency Division Multiple Access (OFDMA), which enables simultaneous transmission of data by different User Equipment (UEs), is considered to be one of the key technologies of IEEE 802.11ax. In order to achieve high throughput rates and low access latency to ensure quality of service (QoS), IEEE 802.11ax supports two uplink access modes: scheduling access and random access. However, how to adaptively and efficiently switch these two access mechanisms in the process of real-time operation of the system, and effectively reduce the drawbacks caused by these two mechanisms is a thorny problem. This paper proposes an evaluation mechanism of network traffic load based on OFDMA-MAC protocol, and its performance is verified by simulation. The simulation results show that the traffic load assessment mechanism effectively improves the network throughput and quality of service (QoS), and also adapts to the dynamic changes in network traffic.

The secure handover Authentication and Key Agreement (AKA) protocols were proposed to fulfill the increasing demands of handover based applications in the wireless network. However, these handover AKA protocols are vulnerable to malicious security attacks, suffer from privacy preservation, key escrow problem and key forward/ backward secrecy (KFS/ KBS). Moreover, these protocols exhibit high overhead and bandwidth consumption during the authentication process. To avoid these problems, we propose an efficient handover AKA protocol by using the double trap-door chameleon hash function in the wireless network. The proposed protocol takes the advantage of trap-door hash key holder to allows the network access. Hence, the proposed handover AKA protocol accommodates all the security features and provides the robust security. Moreover, the protocol avoids the key escrow problem, preserves the privacy of the communication entities and maintains the KFS/KBS. In addition, the formal simulation and security analysis of the proposed protocol are carried out using Automated Validation of Internet Security Protocols and Applications (AVISPA) tool. The security analysis shows that the protocol is free from various known attacks. Furthermore, the performance analysis of the protocol is carried out in terms of communication and computation overhead. The analysis represents that the protocol is secure and efficient compared to the existing handover protocols.

Interconnection of different access network technologies is an important research topic in mobile telecommunications systems. In this paper, we propose an ns-3 architecture for simulating the interconnection of wireless local area network (WLAN) and Universal Mobile Telecommunications System (UMTS). This architecture is based on the architecture proposed by the Third Generation Partnership Project, being the use of virtual interfaces as its main innovation. In order to demonstrate the value of the proposed simulation framework, we implemented the UMTS and WLAN interconnection considering three joint radio resource management strategies for distributing arriving calls. From the simulations results, we can conclude that the proposed simulation architecture is suitable to test and evaluate performance aspects related to the interconnection and joint management of UMTS and WLAN technologies. Copyright © 2012 John Wiley & Sons, Ltd.

IntroductionThe popularity of mobile communication systems has increased remarkably during the last decade and the market demand still continues to increase.As a fundamental part of these systems, antenna is one of the most important design issues in modern mobile communication units.Although there are several similar definitions, an antenna can be mainly described as a device, which transforms the electromagnetic waves in an antenna to radiating waves in an unbounded medium such as air in transmitting mode and vice versa in receiving mode.Because antennas are dependent on frequency, they are designed to operate for certain frequency bands.The rapid growth of mobile communication systems has forced to the use of novel antennas for base and mobile station applications (mobile phone, notebook computer, personal digital assistants (PDA), etc.).Earlier, mobile systems were designed to operate for one of the frequency bands of 2G (second generation) systems, which are Digital Cellular System (DCS), Personal Communications Service (PCS) and Global System for Mobile Communications (GSM) networks.Currently, many mobile communication systems use several frequency bands such as GSM 900/1800/1900 bands (890-960 MHz and 1710-1990 MHz); Universal Mobile Telecommunication Systems (UMTS) and UMTS 3G expansion bands (1900-2200 MHz and 2500-2700 MHz); and Wi-Fi (Wireless Fidelity)/Wireless Local Area Networks (WLAN) bands (2400-2500 MHz and 5100-5800 MHz) where the list of frequently used frequency bands is given in Table 1 ( Best, 2008).Conventionally, because a single antenna can not operate at all of these frequency bands of mobile communication, multiple different antennas covering these bands separately should be used.However, usage of many antennas is usually limited by the volume and cost constraints of the applications.Therefore, multiband and wideband antennas are essential to provide multifunctional operations for mobile communication.A multiband antenna in a mobile communication system can be defined as the antenna operating at distinct frequency bands, but not at the intermediate frequencies between bands.For example, a triple band antenna for GSM 900/1800/1900 bands can cover the frequency bands 890-960 MHz and 1710-1990 MHz (Ali et al., 2003); however, it does not operate properly at the frequencies such as 1200 MHz or 2500 MHz.On the other hand, a wideband antenna operates at every frequency points within a given frequency band.For example, a wideband antenna covering UMTS, extended UMTS and WLAN 2400 bands functions at every frequency points www.intechopen.com

This paper studies QoS (quality of service) management functions that are needed in 3/sup rd/ generation packet data networks. The current architecture of the UMTS (Universal Mobile Telecommunication System) is described. The UMTS QoS architecture and QoS model are presented with important QoS parameters. The QoS management functionality is analysed against the presented QoS architecture and QoS model. The paper presents the functionality that needs to be implemented, to UMTS packet data networks, to be able to provide QoS for end-users. The paper concludes with the description of functions and their locations to be able to provide QoS efficiently in UMTS.

A distinguishing feature of the Universal Mobile Telecommunications System (UMTS) is the support of different levels of quality of service (QoS) as required by subscribers and their applications. To provide QoS, the UMTS backbone network needs an efficient QoS mechanism to provide the demanded level of services on UMTS network. We implement a model to investigate end-to-end quality of service (QoS) provisioning approaches for UMTS networks in a DiffServ IP network environment. The effort was put on QoS classes mapping from DiffServ to UMTS, Access Control, buffering and scheduling optimization. The DiffServ Code Point was utilized in the E2E UMTS QoS provisioning to differentiate different types of traffic. We hybridized our work by applying Resource reservation protocol (RSVP) in routers and hosts. The main advantages and drawbacks are discussed. We found that our proposed model (hybridized model (DiffServ/RSVP)) improves the end-to-end delay and end-to-end variation compared with DiffServ model only, and it is superior to DiffServ regarding to throughput, utilization and packet loss ratio. The overall work guarantees the E2E QoS parameters of each service class, especially for real-time applications and improved the bandwidth utilization. Simulation results show that DiffServ can be an effective candidate for UMTS backbone bearer service.

A novel and efficient user access control scheme for wireless body area sensor networks

Secure architecture for Cloud/Fog computing based on firewalls and controllers

The quality of service (QoS) support in wireless local area networks (WLANs) faces a big challenge due to time-correlated fading channel. Conventional automatic repeat reQuest (ARQ) schemes based on time diversity may result in consecutive retransmission failures degrading QoS severely. This paper proposes a novel Differentiated cooperative medium access control (MAC) protocol, called DC-MAC, to enhance QoS in WLANs based on the IEEE 802.11e architecture. The retransmission is initiated from an appropriate transmission queue of an appropriate relay node instead of the original source to exploit spatial diversity. A novel negative acknowledgement (NAK) feedback mechanism is introduced for loss distinguishing and channel estimation such that cooperative retransmission will be employed only when necessary and only by competent nodes. Simulations conducted on the OPNET platform show that the proposed scheme significantly improves the performances of both multimedia applications and data applications in terms of throughput and delay while supporting service differentiation.

Over the last couple of years, many heterogeneous wireless access technologies have emerged and they have become an integral part of the Internet. In particular, we have experienced an explosive growth in the use of Wireless Local Area Networks (WLANs) and cellular networking technologies (such as Code Division Multiple Access (CDMA), Universal Mobile Telecommunication System (UMTS), General Packet Radio Service (GPRS)). High mobility of wireless users requires that the underlying heterogeneous network infrastructure provides uninterrupted wireless connectivity and service access anywhere, anytime. An additional requirement that is becoming increasingly important for mobile users is the ability to maintain secure connections while on the move across different wireless access technologies. There are some significant challenges (for example, fast, secure handoffs) that need to be overcome to achieve this goal because there is no single end-to-end security protocol that works across both WLANs and cellular networks. We review the various security protocols currently deployed over WLANs and cellular networks. We discuss some of the most recent research efforts on end-to-end security techniques that have been recently deployed across integrated WLAN-Cellular networks. We highlight some of the main benefits and major limitations associated with each security approach. It is hoped that the security solutions discussed will benefit other researchers and designers working to solve the challenge of providing seamless, secure service access across heterogeneous WLAN/Cellular networks.

With the explosively increasing demand of multimedia applications in wireless local area networks (WLAN), Quality of Service (QoS) provisioning has become an important issue. IEEE 802.11 WLAN is the most popular WLAN technology today. In this paper, we propose an adaptive p-persistent based IEEE 802.11 medium access control (MAC) scheme in WLAN. The proposed scheme can maximize the total channel throughput and also can provide the service differentiation to multiple traffic classes. This is achieved by updating the transmission probability for each station in a timely manner based on the network measurements. The simulation results show the scheme can quickly adapt the station transmission probabilities to the desirable values to achieve maximum throughput and QoS provisioning in a dynamic WLAN environment. The simulation results also match well with the theoretical analysis.

In recent years, the wireless local area networks (WLAN) access points (APs) are being deployed rapidly in the offices and the campuses to satisfy the quality of service (QoS) requirements such as network bandwidth. However, many empirical studies show that a large fraction of idle WLAN resources result in the significant energy losses. To reduce the energy consumption without violating the QoS requirement, we propose a QoS-aware AP energy saving mechanism using software defined network (SDN). We leverage the capability of the SDN controller to dynamically monitor the network condition information to estimate the network bandwidth requirement of the devices and then manage the network forwarding to provide seamless handover. Our experimental results show that the proposed scheme can effectively reduce the number of power-on WLAN APs while still providing QoS guarantee, such as network bandwidth and handover cost.

Wireless local area networks (WLANs) are widely used in airports, enterprises, schools, shops etc. Now a day, WLANs are growing very fast in aforesaid sectors and others. In their, security (specially authentication) is a vital issue because of the wireless medium being available to everybody in open space. The users of wireless network today aspire to have a tight security and good performance equivalent to those of the wired networks. As such, we have many authentication procedure for WLAN like Wired Equivalent Privacy, IEEE 802.1x etc. provides security and good authentication support. However 802.11i is having the problem of Denial of Service attacks, and Man in the Middle attack high delay in the authentication and a complicated key distribution procedure as well as appreciable computational load on the access point. The current paper attempts to provide such authentication procedure which is characterized with improved security along with minimized the authentication delay.