ACADEMICIA Volume 2, Issue 4 (April, 2012) ISSN ACADEMICIA: ROUTING ALGORITHM FOR SECURE BROADBAND NETWORKS ER.

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1 Published by: ACADEMICIA: A n I n t e r n a t i o n a l M u l t i d i s c i p l i n a r y R e s e a r c h J o u r n a l ROUTING ALGORITHM FOR SECURE BROADBAND NETWORKS ABSTRACT ER.GURJEET SINGH* *Assistant Professor, Department of CSE/IT, Desh Bhagat Institute of Engineering & Management, Moga, India. Broadband wireless access networks are considered to be enterprise-level networks providing more capacity and coverage. Wireless networking has offered an alternative solution to the problem of information access in remote inaccessible areas where wired networks are not cost-effective. They have changed the way people communicate and share information by eliminating worrisome factors of distance and location. This paper provides a technical analysis of alternatives for implementing last-mile wireless broadband services. It provides detailed technical differences between (Wi-FI) wireless networks with (WiMAX), a new technology that solves many of the difficulties in last-mile implementations. This paper proposes a new routing protocol that integrates WLANs and WMANs, allowing seamless interconnectivity. KEYWORDS: WiFi, WiMAX, Broadband Wireless Networks. I. INTRODUCTION Broadband wireless access (BWA) is increasingly gaining in popularity as an alternative lastmile technology to DSL lines and cable modems. Following the hugely successful global deployment of the wireless local area network standard, deployment of the IEEE d and e wireless metropolitan area network standards is currently in progress. This technology aims to provide broadband wireless access to residential and small business applications, as well as enable Internet access in countries without any existing wired infrastructure in place. The latter version (802.16e) attempts to provide mobility to the end user in a MAN environment. Wireless technologies need to be examined from two perspectives: that of access network and the backhaul network. Even the access networks are principally categorized into two groups. There is the cellular network group and the broadband wireless 60

2 access group, popularly known as the 802.xx family. The 802.xx family has seen the proliferation of different standards since its inception. Such diversity has been necessitated by the number of properties desired from them. II. OVERVIEW OF WI-FI & WIMAX THE IEEE (WI-FI) WiFi is a trade mark of the WiFi Alliance (Wireless Ethernet Compatibility Alliance), which is in charge of testing and certifying the interoperability of devices based on the IEEE standard [3]. WiFi allows APs a coverage radius, or hotspot, of approximately 100m in interior spaces [3]. Meanwhile, WiFi exterior coverage can cover a radius of approximately 300m, depending on environmental conditions [7]. The transmission speed of the different WiFi standards ranges from 11Mbps until 54Mbps [3]. There are three well known wireless family standard widely used today. B. THE IEEE B A refined standard for the original and was successful due to its high data rates of 11 Mb/s - range of 100 m to a maximum of a few hundreds meters, operates on 2,4 GHz unlicensed band b is the most widely deployed wireless network within the wireless families [4, 5]. It uses the DSSS modulation technique that is more reliable than the FHSS. C. THE IEEE G The IEEE g wireless standard also operates on the 2.4 GHz band and has similar range and characteristics as the b. It has a data rate of 54Mbps. The g has backward compatibility with b and differs only on the modulation technique; it uses Orthogonal Frequency Division Multiplexing (OFDM). This then makes the b devices not able to pick the signal from the g devices D. THE IEEE A Operates in the 5 GHz band with a maximum data rate of 54Mbps. The major disadvantage in deploying a with the other standards b and g is that, they cannot co-exist, as they operate on different frequency bands b/g operates on the 2.4 GHz spectrum. There are some wireless card and access points which are compatible to all the three standards thereby supporting the 2.4GHz and 5GHz frequencies. WiFi s advantages include: its use of a non-licensed frequency band. its fewer international regulatory restrictions. 61

3 its infrastructureless architecture that allows for ubiquitous functioning and dynamic growth. its low cost. its mobility without network connection breaks. WIFI S DISADVANTAGES INCLUDE III. WIMAX its use of the 2.4GHz spectrum, which is susceptible to interference. its higher energy consumption when compared to other standards. WiMAX is the acronym for Worldwide Interoperability for Microwave Access and its architecture is based on broadband point-to-multipoint wireless access [3]. WiMAX was created in 2001 to promote the IEEE standard. This standard was finally approved in June 2004 [4]. The standard provides for fixed and mobile WiMAX in d and e, respectively [9]. Some important characteristics of WiMAX include: Power: Varies with band. Profiles from 100 Mw up to 2W Configuration: P-P and P-MP Cellular Spectrum: Initially 3.5 GHz licensed and 5.8 GHz unlicensed bands Radio interface: OFDM, using 256 tones Access Protocols: Downstream - TDM (Broadcast), Upstream - TDMA with access contention Security via station authentication and encryption Data rates variable with channel bandwidth 3.5 MHz in 3.5 GHz band, 20 MHz in 5.8 GHz band Actual realizable data rates are ~ 2b/Hz Maximum range ~2Km for indoor Non-LOS cellular service at 3.5 GHz 62

4 APPLICATIONS OF WIMAX WiMAX will allow people to go from their homes to their cars, and then travel to their offices or anywhere in the world, all seamlessly[7]. WiMAX can serve the business, residential and mobile segments. The applications in these areas are listed below: RESIDENTIAL USERS Basic voice services, low cost domestic & international calls Basic (dialup speed) to advanced (over 1Mbps) data connections Bundled voice and data services BUSINESS USERS Basic data connectivity for small businesses Advanced data services to medium and large businesses Feature-rich, low cost voice services (VoIP) MOBILE USERS (MOBILE WIMAX ONLY) Data connectivity for mobile workforce Data connectivity for international visitors IV. ARCHITECTURE OF WIFI & WIMAX Ali-Yahiya et al. propose an architecture where the WiFi and WiMAX networks and their traffic routes are separated by dedicated gateways to provide interconnectivity [6]. The main characteristic of this architecture is that it employs an overlapping area between a WLAN and a WMAN hotspot, where they interconnect at a BS and an AP. The WMAN coverage area expands using the WLAN hotspots. More than one AP can be located near the limit of the WMAN s coverage area. The authors assume that WiFi network APs are connected to the WiMAX network by means of a gateway that permits bidirectional interconnectivity. 63

5 FIGURE 1 ARCHITECTURE OF WIFI & WIMAX To better integrate WiFi and WiMAX technologies, it is important to identify the differences between them, including: WiFi channels use a specific band frequency while WiMAX permits users to select the channel requirements. WiMAX uses licensed frequencies while WiFi employs unlicensed ISM frequency bands. WiFi has a range of approximately 10m while WiMAX can cover several kilometers. WiMAX is a MAN protocol that provides an alternative to DSL and cable modem technologies, providing broadband access for the last mile as it acts as a backbone for WiFi hotspots. Quality of service (QoS) and mobility are the most common challenges, thus require specific protocols to integrate different types of wireless networks. The most significant problem in terms of QoS is the actual handoff, where nodes must pass information between cells. An important aspect to consider is that the basic support for QoS differs significantly between WLAN and WMAN because of the different architectures, and more specifically, the specifications of their physical and MAC layers [6]. 64

6 WiMAX technology supports both PMP and Mesh. A WiMAX PMP network provides last mile access to broadband Internet services by organizing the nodes in a manner that is similar to cell phone networks because it uses a BS. Meanwhile, in mesh topology, an ad hoc network functions independently of the BS. Each node can simultaneously transmit and receive information from neighbor nodes. Additionally, they can send information using a multihop strategy to communicate with nodes that are further away. The security mechanism of the IEEE standard focuses principally of MAC layer security which does not, however, provide sufficient security for multihop transmissions. Consequently, the IEEE standard is insufficient to meet the requirement of WiMAX Networks. V. SECURITY FEATURES OF IEEE The IEEE WLAN or WiFi specification has identified several services to provide a secure operating environment. The security services are provided largely by the Wired Equivalent Privacy (WEP) protocol to protect link level data during wireless transmission between clients and access points. WEP does not provide end-to-end security, but only for the wireless portion of the connection. However, there are a number of problems with the WEP protocol and its vulnerabilities significantly limit its ability to safeguard data. Commonly available tools such as AirSnort, WEPCrack and dweputils have the ability to crack WEP keys by analysing traffic from totally passive data captures. An improvement on WEP is the Wi-Fi Protected Access (WPA) which was introduced in The three basic security services defined by IEEE for the WLAN environment are: AUTHENTICATION: provide access control to the network by denying access to client stations that cannot authenticate properly. This service addresses the question, Are only authorised persons allowed to gain access to my network? CONFIDENTIALITY: Are only authorised persons allowed to view my data? INTEGRITY: Ensure that messages have not been modified in transit between the wireless clients and the access point in an active attack. This service addresses the question, Is the data coming into or exiting the network trustworthy has it been tampered with? VI. THREATS There have been many reports describing attacks on wireless networks that expose organisations to security risks. These attacks, either active or passive, are essentially on confidentiality, integrity and network availability. According to the US National Institute of Standards and Technology (NIST) there are six different types of attacks under passive and active categories against IEEE networks: PASSIVE ATTACK: An attack in which an unauthorised party gains access to an asset and does not modify its content (i.e. eavesdropping). Passive attacks can be 65

7 either eavesdropping or traffic analysis (sometimes called traffic flow analysis) and are described below: EAVESDROPPING: The attacker monitors transmissions for message content. An example of this attack is a person listening into the transmissions on a LAN between two workstations or tuning into transmissions between a wireless handset and a base station. TRAFFIC ANALYSIS: The attacker, in a more subtle way, gains intelligence by monitoring the transmissions for patterns of communication. A considerable amount of information is contained in the flow of messages between communicating parties. ACTIVE ATTACK: An attack whereby an unauthorised party makes modifications to a message, data stream, or file. It is possible for these attacks to be detected but they may not always be preventable. Active attacks may take the form of one of four types (or combination thereof): masquerading, replay, message modification, and denial-of-service (DoS). These attacks are defined below: MASQUERADING: The attacker impersonates an authorised user and thereby gains certain unauthorised privileges. REPLAY: The attacker monitors transmissions (passive attack) and retransmits messages as the legitimate user. MESSAGE MODIFICATION: The attacker alters a legitimate message by deleting, adding to, changing, or reordering it. DENIAL-OF-SERVICE: The attacker prevents or prohibits the normal use or management of communications facilities. VII. COMPARISON OF WIFI AND WIMAX A start can be made by saying that comparing WiMAX and WiFi is comparing two different frameworks. WiMAX has much longer distances and may (or will) also include mobility between cells. In fact, WiFi and WiMAX are complementary, specifically if WiMAX is used for the backhauling of WiFi. There is also a difference in the chronology. WiFi is a WLAN, based on the IEEE standard, published in 1997, and the b variant, published in WiMAX is a BWA system, including mobility, based on the IEEE standard, published in 2004, and the e variant, published in February 2006 (in addition to other amendments). Hence, if we consider the standard or the products, there is a difference of about six years between the two. The main points of comparison of the three technologies that have been discussed in this paper are listed in table1. 66

8 Technology WiFi WiMAX Application Wireless LAN, Internet Metro Area Broadband Internet Connectivity Range 100m 50km Frequency Range 2.4 GHz 2-11GHz Data Rate Mbps 75Mbps Network P2P IP Network Topology Infrastructure(Ad-hoc also possible) Infrastructure Access Protocol CSMA/CA Request/Grant Key Attributes Wider Bandwidth Throughput TABLE 1 COMPARISON BETWEEN WIFI & WIMAX VIII. PROPOSED ROUTING ALGORITHM The goal of our algorithm is to afford users of ad hoc network broadband service using devices that can select the best route in terms of bandwidth, battery residual energy and distance. The proposed protocol can carry out the necessary hops to send and receive data within a WiMAX network. If, a connection is broken, the algorithm is designed to automatically reconnect. AODV is a routing protocol that is used to connect mobile nodes in Ad hoc networks. Important characteristics of AODV include: quick adaptation to dynamic conditions rapid data processing speed low network utilization its unicast route mechanism that permits easier data transmission between origin and destination pairs. The main characteristics of AODV algorithm is its reactive route discovery mechanism, that begins only when a node requires information from neighbor nodes. This strategy allows AODV to reduce the number of control packets sent, thus reducing overhead. AODV also maintains dynamic routing tables and its routing mechanism responds quickly to broken links by establishing alternative routes. 67

9 Figures 2 show the flow diagrams for the proposed routing algorithm. Source node requesting transmission begins with a RREQ packet until it can reach a destination node or the WiFi/WiMAX gateway. FIGURE 2 PROPOSED ROUTING ALGORITHM If the destination node is outside of the coverage area of the WiFi network, the AP should retransmit the RREQ packet. After, the WIFI/WIMAX gateway or destination node receive the packet, it will reply a RREP packet to the source node. CONCLUSION In this paper we discussed the algorithm for secure broadband networks. In the future, other algorithms can be developed using the same simulation scenario under different conditions in order to obtain quantitative data to determine which protocol best for routing WiFi and WiMAX technologies. WiMAX has a large number of mechanisms and is expected to be used for many 68

10 applications. The near future will tell which of these mechanisms will be implemented, how they will be implemented and the mechanisms that will be updated by the standardisation bodies. REFERENCES [1] Gurjeet Singh, Dr.Jatinder Singh(2011) Comparative Analysis of Broadband Wireless Technologies IJCST Vol. 2, Issue 4, Oct - Dec pp [2] R. Bera, B. Paul, A. Guchhait, S. Sil. N.B. Sinha, y S. Dogra. Wireless Embedded System for Multimedia Campus Network Utilizing IEEE N (draft) and WiMax Radio, en Proc Wireless and Optical Communications Networks, pp.1-5. [3] S. Jindal, A. Jindal, y N. Gupta. Grouping WI-MAX, 3G and WI-FI for wireless broadband, en Proc First IEEE and IFIP International Conference in Central Asia. [4] A. Ian F., W. Xudong, W. Weilin. Wireless Mesh Networks: A Survey, Computer Networks, Volume 47, Issue 4, 15 March 2005, pp [5] T. Su-En. WiMax-Prospect and New Business Models, en Proc G and Beyond, th IEEE International Conference on, pp.1-5. [6] T. Ali-Yahija, K. Sethom, y G. Puiolle. Seamless Continuity of Service across WLAN and WMAN Networks: Challenges and Performance Evaluation, Proc IEEE/IFIP International Workshop, pp [7] S. Dhawan. Analogy of Promising Wireless Technologies on Different Frequencies: Bluetooth, WiFi, and WiMAX, en Proc Wireless Broadband and Ultra Wideband Communications, AusWireless The 2nd International Conf. [8] IEEE and WiMAX: Broadband Wireless Access for Everyone, Intel Corporation,