Wireless Local Area Networks WLANs Security Computer Science Essay

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This thesis studies the security missions of wireless LANs (WLANs), from its vulnerability as well as alternative solutions. The suggested research plan includes experiments on studying security and achievement aspects of each of the alternative solutions. Appendix A contains accumulation technical designations, which are referred on wireless LANs and referred technology, and their respective definitions.

The rest of the proposal is composed of the following sections:

An introduction in a WLAN (this section): Kinds of WLANs, of standards and of security characteristics

Definition of the research problem

Propose the Alternative solutions to the problem such as IEEE 802.1x, VPN (virtual private network), LEAP (Lightweight Extensible Authentication Protocol), and SSL (Secure Socket Layer).

Setup of the test beds and configuration of the experiments

Research plan and timelines


A wireless LAN (WLAN) is analogous to a wired LAN but radio waves being the transport medium instead of traditional wired structures. This allows the users to move around in a limited area while being still connected to the network. Thus, WLANS combine data connectivity with user mobility, and, through simplified configuration, enable movable LANs [WLANA Resource Center, 1999].

Due to the flexibility WLAN is popular in recent years in LAN environment. It provides solution for home and office automation. It's typical communication range is single building or a cluster of buildings i.e., 100-1500 meters (Mohammad Illyas, 2003).

WLAN should assure the same requirements that are the characteristic of any LAN, that are capacity, full connectivity among attached stations and broadcast capability should be maintain. For achieving these characteristics wireless design faces some issues that are transmission medium security, power consumption, bandwidth limitation of air interface and bandwidth (Theodore S. Rappaport, Wireless Communications, Principles and Practice, Prentice Hall, 1996. W. Stallings, Wireless Communications & Networks).

There are two different approaches are used to implement wireless LAN

Infrastructure based

Ad hoc networking Approach

In infrastructure based there is a centralized control for each cell (Access Point) which is connected with the wired network to provide internet access to mobile devices, however Ad hoc networking is a peer to peer network which is formed by the number of station which are in range connect through each other through automatic configuration and set up a temporary network. There is no fixed controller; controller is selected among the devices which are taking part in communication. If the devices do not require access to the network resources they make a network without access point. Examples of these types of networks are conference room network, fire fighters network, Army personnel network. Typical wireless LAN implementations include 802.11 (Wi-Fi) and Hiperlan2. Under 802.11a and 802.11b, data can reach transmission speeds between 11 Mbps to 54 Mbps (L. Goldberg, (1995), (D. L. Lough, Tutorial on Wireless LANs and IEEE 802. 11, "Virginia Polytechnic Institute and State University.

Generally a WLAN (in mode of infrastructure, to see below) is composed of a central point of connection called the access point (AP). It is similar to a hub or a switch in traditional star topology based wired local area networks. The access point transmits the data between various nodes of a wireless local area network and is useful in the majority of the cases of only link between the WLAN and the wired LAN. A typical access point can handle a beautiful quantity of users in a ray of approximately 300 feet. The nodes without wire, also called the customers of a WLAN are usually composed of the GCV of office computer, the portable computers or PDAs equipped with wireless interface cards (Randall K. Nichols, Panos C. Lekkas, 2001).

1.2- Types of Wireless Networks:

According to the 802.11 standard (John Vollbrecht, 2001) describe following three types of wireless networks.

1.2.1 Independent Basic Service Set (IBSS):

IBSS (commonly referred to as Ad Hoc Network) is logically comparable to a Peer-to-Peer network in case of a wired LAN as shown in Fig.1. In case of IBSS different end nodes communicate without any Access Point and thus without any connection to a wired network. It is used to quickly set up a wireless network (to avoid the hidden node problem [1] ) such as for a group meeting or at a convention centre or at an airport, etc.

IBSS (generally indicated under the name of ad hoc network) is logically comparable with a network of Par-with-Par in the event of wired LAN as shown in figure 1. In the event of different end nodes of IBSS communicate without any access point and thus without any connection to a wireless network. It is employed to quickly establish a network without wire (in order to avoid the node hidden problem) as for a meeting of group or in a centre of convention or an airport, etc.


Fig.1 Ad-hoc Mode [2] 

Fig.2 Infrastructure Mode

1.2.2 Basic Service Set (BSS): BSS (generally indicated under the name of a network of infrastructure) is composed of only one access point according to the figure 2. Any communication between two unspecified nodes must pass by access point (AP). The sector of insurance is increased considerably compared to an IBSS.

1.2.3 Extended Service Set (ESS):

An ESS consists of multiple BSSs each having a single Access Point. Access Point in each BSS is connected to a distribution system that is usually a Wired Ethernet Network.

Fig.3 Extended Service Set (ESS)

1.3- Wireless Networking Standards

According to WLANA Resource Center (April 17 2002), Institute of Electrical and Electronics Engineers (IEEE) has specified various WLAN standards such as 802.11, 802.11a, 802.11b, and 802.11g. Some important standards in the context of this thesis are summarized below in Table




IEEE 802.11

Data rates up to 2Mbps in 2.4-GHz ISM band, Coverage (m) 40 to 400, Mobility Roaming between APs by mobile Internet

Protocol (IP) devices, Security 128-bit WEP

July 1997

IEEE 802.11a

Data rates up to 54Mbps in 5-GHz UNII band, Coverage (m) < 100

Mobility Roaming between APs by mobile IP devices,

Security 128-bit WEP, 64-bit WEP, 152-bit WEP

Sept 1999. End user products began shipping in early 2002

IEEE 802.11b

Data rates up to 11Mbps in 2.4-GHz ISM band, Coverage (m) 40 to 400,

Mobility Roaming between APs by mobile IP devices,

Security 128 bit WEP.

Sept 1999. End user products began shipping in early 2000

Table 1. IEEE WLAN Standards

1.3.1- IEEE 802.11b SECURITY FEATURES: The security features provided in 802.11b standard are as follows (John Vollbrecht, 2001):

A. SSID - Service Set Identifier

SSID behaves like as identifier of WLAN. Thus all the devices trying to connect itself to a particular WLAN must be configured with the same SSID. One adds it to the header of each package sent above the WLAN (with a BSS) and checked by an access point. A device of customer cannot communicate with an access point unless it is configured with the same SSID as the access point.

B. WEP - Wired Equivalent Privacy

According to standards of 802,11, (WEP) has been understanding in order to supply "the confidentiality that is subjective equivalent to the confidentiality of a wired local area network (LAN). It does not employ the cryptographic techniques in order to increase to the privacy (Interlink Networks Resource Library, 2002).

The detailed lists of the IEEE for wired LANs do not include the cryptography as a requirement. That is because approximately all the this LANs are fixed through physical means which the structures walled and the controlled entrance to construction etc However no such physical contour can in the event be supplied of WLANs that justifies therefore the requirement of a cryptography mechanism.

WEP supplies to the symmetrical cryptography using the WEP key. Every node must be shaped manually with the same key of WEP. The transmission station number the message using the WEP key while the reception station decrypts the message using the same key of WEP. WEP uses the figure of flow RC4.

C. MAC Address Filters

Assembled in this case will the access point, around connection and requests for the setting up a connection by only those nodes to assume their MAC addresses with the point of entrance to be registered. This draft supplies an additional security layer.

2 - Problem Definition

Everywhere existing network entrance without lines is the main attraction underlying wireless network development. Although this seems as sufficient attraction, other side of the illustration exists. Before they go all wirelessly organizations should understand first, how wireless networks could be vulnerable some kinds penetration methods.

2.1 INVASION & RESOURCE STEALING: Resources of a network know different devices such as printers and Internet access etc. First the attacker tries to tighten and determine the access parameter for this certain network. for example if network uses the MAC address created filtering of the clients, everything must do an intruder is MAC address and assigned IP address for a certain client to determine. The intruder waits, until this valid client goes away from the network and then he begins, the network and its operational resources with the appearance to use as valid users.

2.2 TRAFFIC REDIRECTION: An intruder can change therefore know the way of traffic and the packets, which are intended for a certain computer, for attacking station to be readdressed. for example ARP tables (the MAC address contained to the illustrating IP address), into which switches of a wired network are manipulated, so that packages for a certain wired station can reroute themselves for attacking station.

2.3ROUGE ACCESS POINT: A rogue access point is one, which is attached by an attacker (normally within the general ranges like divided office space, airports etc.) around traffic of the wireless clients to assume, to whom it appears as valid Authenticator. The packets, which are taken captured therefore, can be used to extract over sensitive information or can for further attacks, be finally used before one into the correct network are again inserted.

2.4 DENIALOF SERVICE (DOS) ATTACK: A DOS can take two forms jamming and deauthentication. Network jamming can occur when a high powered transmitter is placed within network range on the same spectrum as the network. A major concern for this form of attack is that it is difficult to detect and devices which use the 2.4-GHz spectrum can cause network jamming - such as Bluetooth devices and microwave ovens. A deauthentication attack exploits the fact that control and management information is broadcast unencrypted over the wireless network. A malicious attacker can capture this information and use it to deauthenticate a device which is connected to the network. This is the first step in either a man-in-the-middle attack or capturing logon credentials from the device as it tries to reconnect (Woodward, 2005).Woodward, A. 2005. 'Recommendations for wireless network security policy'. [Online] Microsoft Academic Research. Available at: http://scissec.scis.ecu.edu.au/anzsys08/proceedings/2005/aism/woodward.pdf [Accessed: 13may2010].

These concerns relate to wireless networks in general. The security concerns raised specifically against IEEE 802.11b networks [4] are as following.

2.5 MAC ADDRESSES Authentication: Such sort of authentication establishes the identity of the physical machine, not its human user. Thus an attacker who manages to steal a laptop with a registered MAC address will appear to the network as a legitimate user.

2.6 ONE-WAY Authentication: WEP authentication is client centered or one-way only. This means that the client has to prove its identity to the Access Point but not vice versa. Thus a rogue Access Point will successfully authenticate the client station and then subsequently will be able to capture all the packets send by that station through it.

2.7 Static WEP Keys: There is no concept of dynamic or per-session WEP keys in 802.11b specification. Moreover the same WEP key has to be manually entered at all the stations in the WLAN.

2.8 SSID: Since SSID is usually provided in the message header and is transmitted in clear text format, it provides very little security. It is more of a network identifier than a security feature

2.9 WEP KEY encryption: The use of a small initialization vector (IV) means that in a high traffic environment it is probable that the same IV will be used more than once in a day. This makes it feasible for an attacker to bypass encryption system. (Woodward, 2005) Also issues have been discovered with the RC4 algorithm used to generate the key stream that synchronises transmitting and receiving devices. It has been shown that the secret key can be obtained by capturing 5 to 6 million packets of data to correlate the first few bytes of the keystream with the generate key. (Borisov, 2005)

This thesis will try to address in depth the security limitations of WEP included in IEEE 802.11b specifications. To combat the WEP vulnerability for WLAN security, I plan to investigate the following solutions: IEEE 802.1x, VPN (Virtual Private Network), Cisco LEAP (Light Weight Authentication Protocol), and SSL (Secure Socket Layer). These alternative approaches will be studied and tested for their respective security strength and performance overhead.


3.1- IEEE 802.1x: IEEE 802.1x is a port based authentication protocol. There are three different types of entities in a typical 802.1x network including a supplicant, an authenticator and an authentication server. When applied to 802.11b LANs, the 802.1X specification includes two main features(Interlink Networks Resource Library, 2002).

Logical Ports: Since, differently than wired networks, wireless stations are attached not to the network with physical means, they must have any kind of the connection relation with one point of entrance of using for the WLAN. This connection is made, by letting the clients and the access point of each other MAC address know. This combination of MAC address of the access point and the station serves as a logical gate. This serves then as a destination address into the EAPOL minutes from deceiving. EAPOL standard is defined for sending EAP announcements over IEEE 802.11 created connections. . EAP message exchanges using EAPOL occurs at Data Link layer i.e. only MAC Addresses are involved. Higher minutes such as IP were not present instantiated. EAPOL field data format is shown in the fig: 4

2-byte Type code assigned to EAPOL

Fig.4 EAPOL Frame Format [3] 

Key Management: IEEE 802.1x specifications do not emphasize on using WEP key for encryption. This is because key information is passed from Access Point to a station using EAPOL-Key message. Thus keys are generated dynamically, per-session basis authenticates with the Authentication Server by using EAPOL to communicate with the Access Point. Messages are exchanged between Supplicant and Authenticator to establish Supplicant's identity. The Authenticator then transfers Supplicant's information to the Authentication Server using RADIUS. Authentication Server instantiates authentication mechanism by issuing a challenge message. All communication between Authentication Server and Supplicant passes through Authenticator using EAP over LAN (i.e. EAPOL) and EAP over RADIUS accordingly. This creates an end-to-end EAP conversation between Supplicant and Authentication Server. Once Authentication Server authenticates the Supplicant, the Authenticator delivers key parameters (and not the actual key) to the Supplicant. Typical configuration of WLAN using IEEE 802.1x is shown in Fig.5.

IEEE 802.1x specifications do not highlight on using WEP key for encryption. This is, because key information is led from the access point to a station with EAPOL key message. Thus keys are generated dynamically, per-session basis authenticates with the Authentication Server by using EAPOL to communicate with the Access Point. Announcements are exchanged between Supplicant and Authenticator, in order to manufacture identity Supplicants. The Authenticator brings then information to Supplicants on the authentication operator with RADIUS. Authentication operator of instantiates authentication unit by the expenditure of a challenge announcement. All communication between authentication operator and Supplicant exceeds by Authenticator with EAP over LAN (i.e. EAPOL) and EAP over radius accordingly. This causes a successive EAP discussion between Supplicant and authentication operator. As soon as authentication operator authenticates the Supplicant, the Authenticator key parameter (and not the address key) supplies to the Supplicant. Typical configuration of WLAN, which uses IEEE 802.1x, is shown in Fig.5.

Supplicant Authenticator Authentication Server

Fig.5 IEEE 802.1x in 802.11 WLANs [4] 

3.1.1- Association & EAP Authentication Procedure

IEEE 802.1X specifies two distinct ports. The first port is uncontrolled and allows only authentication messages (EAP messages) to be exchanged. Second port is controlled and allows the exchange of frames only if the port is authorized.

3.1.2- Advantages

Dynamic Session Key Management: 802.1x allows dynamic session key encryption.

Open Standards Based: 802.1x leverages existing standards, EAP and RADIUS.

Centralized User Administration: Since 802.1x supports RADIUS, authentication, authorization and accounting are centralized.

Low overhead; 802.1x does not involve encapsulation, so it adds no per-packet overhead.

User Based Identification


VPN technology supplies the means to transmit data surely between two network devices over an uncertain data transfer means (Pierre Trudeau, 2001). VPN technology was used successfully in wired network, particularly if using Internet as a physical means. This success of VPN in wired networks and associated security restrictions of the wireless networks requested developers and managers to unfold it in case of the wireless networks.

3.2.1- Need for VPN in Wireless Networks

Wireless network connection is more vulnerable and less secure than wired network connection. In order to come with a security solution for wireless networks above, we would like to emphasize first two important aspects of the wired networks in their security expressed:

There is no specification of any encryption standard to be implemented in case of wired LANs. This is, because normally the wired networks (cables, routers, etc) are within the enclosed physical structure of an organization.

Even if the medium used is insecure (e.g., the Internet), to implement security, emphasis is laid on Network Layer and above instead of Physical Layer. For example, some form of user authentication or Internet Firewall can be implemented. This is because in case of Internet, there is no one physical dedicated link between the two end stations. Thus Physical Layer cannot be relied upon providing substantial security.

In a VPN, an organization uses the bandwidth of the Internet to establish private, secure connections between its remote offices and/or employees. Each of the remote users connects to the local ISP in the same manner that is used for Internet access: dial-up, cable, DSL, ISDN, T1 or wireless. A process called "tunneling" is used to carry the data over the Internet. However, tunneling alone does not ensure privacy. To secure a tunneled transmission against interception, all traffic over a VPN is encrypted for safety.

Figure 6: Virtual Private Network (VPN) with tunneling over the internet [5] .

VPN works by creating a tunnel, on top of a protocol such as IP. Fig 6 represents a typical wireless LAN configuration using VPN. VPN technology provides three levels of security (L. Goldberg, (1995), :

Authentication: A VPN server must authorize each user logged on to a specific wireless station and it also try to connect with a WLAN by use the VPN client. Therefore authentication is not machine based so it is a user based.

Encryption: VPN provides a protected tunnel on the top of essentially unprotected medium like as internet. In which, traffic pass through the tunnel to give another level of data confidentiality.Thus even if an intruder manages to get into the tunnel and intercepts the data, that intruder will have to go through a lot of effort and time decoding it (if he is able to decode it).

Data authentication: It guarantees that all traffic is from authenticated devices thus implying data integrity.


Cisco LEAP or EAP Cisco wireless is an authentication 802.1X kind for wireless LANs, which supports strong mutual authentication between the client and a radius operator. LEAP is a component of Cisco wireless security system. Cisco imported LEAP in December 2000 as introductory way to improve the entire security of the wireless LAN authentication fast. LEAP is, a market-proven EAP authentication kind unfolded far.

Cisco's LEAP fills two noteworthy WLAN security holes (Interlink Networks Resource Library, 2002):

Mutual Authentication between Client Station and Access Point: I have described in section 2 (problem representation) about the points of Rogue Access Point. This was because of the One Way, client cantered authentication between the client and the access point. LEAP requires two-way authentication, i.e. a station can also examine the identity of the access point, before it accomplishes the connection.

Distribution of WEP Keys on a Per-session Basis: In contrast with the static keys of WEP in 802.11 detailed lists, the LEAP protocol supports the notion of the dynamic keys of session. This key is generated by the Radius Server and Cisco client independently. Therefore the key is not transmitted through the air in which it could be intercepted.


The SSL is basically security protocol of emergency used in nearly 100% of the secure transactions of the Internet. Essentially, the SSL transforms a typical secure protocol of transport (which the TCP) in order to make a secure communications adapted to lead the sensitive transactions. The SSL protocol defines the methods by which a secure communications channel can be established-it does not indicate which cryptographic algorithms need to be used.

The SSL supports many different procedures and serves from structure for which the cryptography it can be used in a convenient and distributed way. Since WEP alone does not ensure secure wireless communications, people are encouraged to use applications that provide encryption such as SSL-based secure websites.

The SSL protocol runs above TCP/IP and below higher-level protocols such as HTTP or IMAP (Refer to Fig. 7.). It allows mutual authentication between SSL Client and SSL Server and then form an encrypted connection.

Fig.7 SSL runs above TCP and below High Level Protocols [6] 

3.4.1- Some advantages of SSL are given below:

SSL provides an encrypted communication between client and the serer in order to make communication safe and secure.

It also provides the authentication between server and the client

It is one of most common standards on today's web browser.

Easy to establish sessions

It is cheaper solution as compare to the others.



There are two computers desktop bases Intel. They both will be associates with the access point in order to generate an infrastructure based WLAN. One of them will act as server who accommodates a program that generates sample data. Moreover it acts as a server of VPN and/or like server of authentication, according to the bottom method that is employed in an experiment. According to calculating it will act as from customer of VPN, the LEAP or the SSL etc, according to the bottom method that is employed in an experiment.

4.1.1- Hardware Configuration


Intel Pentium II 400MHz



Network Adapter

Cisco Aironet 350 Series Wireless LAN Adapter

4.1.2- Software Configuration

Operating System: Windows 2000 Professional

ACU (Aironet Client Utility): This program of usefulness comes with the card of Aironet. It is used to perform user level diagnostics on the Cisco Wireless LAN adapter card. It allows us to modernise firmware, look at the current condition of the device, we observe statistics currents of the device and carry out a connection test in order to estimate the performances of the RF connection to several places in our zone.

The customer is used in order to obtain the IP address of a wireless Ethernet device based on the device MAC ID. To set up the IP address and SSID user can use this utility if the device is still in default state


Intel based Dell Laptop will be used to try to crack the WEP key in the WEP enabled WLAN configuration. (Refer to Fig.7.) It will host a program like 'AirSnort' for cracking WEP key.


Processor: Intel Pentium III 600MHz

RAM: 256MB

Network Adapter: Cisco Aironet 350 Series Wireless LAN PCMCIA Adapter

4.2.2- SOFTWARE CONFIGURATION: The same as the desktop.


The access point is the absolute necessity in the event of the wireless LAN that works in the way of the infrastructure. All the traffic between the two computers in the wireless network must pass through this access point. Therefore it is analogous to a hub or a switch in wired LAN.

Make and Model: Cisco Aironet 350 Series

Data Rates Supported: 1, 2, 5.5, 11 Mbps

Network Standard: IEEE 802.11b

Uplink: Auto-Sensing 10/100BaseT Ethernet

Frequency Band: 2.4 to 2.497 GHz

Network Architecture: Infrastructure

Wireless Medium: Direct Sequence Spread Spectrum (DSSS)

Supports IEEE 802.1x- based Extensible Authentication Protocol (EAP) services that provide centralized, user-based authentication and single-user, single-session encryption keys

Supports Automatic channel selection, Cisco Discovery Protocol (CDP), Dynamic Host Configuration Protocol (DHCP), and BOOTP services to simplify installation and management of WLAN infrastructures


With the existing small articles indicated above, four different security units were introduced. A Java based program would have to be accomplished and (on the server side) for all units (described in Sec.4.5), which would empty data continuously to the client for security and result analysis. Some these units require extra software configurations in addition, which were fulfilled, by making somewhat necessary configuration changes in the access point and Cisco client software setup (e.g. in case WEP and the LEAP) and also by using the third party software. This third party software would include:

Airsnort utility for cracking of WEP key. (Currently widely used version of Airsnort is Linux based. If windows version could not be obtained then one of the desktop PCs would be installed with Linux operating system.)

Radius (AAA) Server. This would be an absolute requirement in the case of Cisco LEAP approach and can also be used in the VPN approach.

VPN Server and VPN Clients for the VPN approach. Any shareware distribution of VPN server and client can be used for this purpose. SSL enabled client and server for the SSL based approach


To be used the main approximation is the comparable approximation i.e. to compare security characteristics and capability characteristics of all over described four approximations.


To compare security features, for every approach there would be Theoretical Analysis of the problem in hand Testing (by trying to hack and attack), for example, Airsnort for WEP For the other approaches attempts would also be made to develop an approach to test them after extensive study in their security mechanisms is conducted.


A Java application is used, in order to produce sample data. Care will be taken to make sure that all these four approaches are tested for performance considerations under similar hardware and software environments. In order to examine the achievement of all approximations indicated above, a program can be written or any third party tool can be used. We can also use third party software like "Net Stumbler", in order to accomplish the rigorous performance inspection.


A tentative thesis timeline is shown in Table 2 as follows:


Intended Activity


2 week

Client Server Testing (Java) program

Initial Study regarding IEEE 802.11B security limitations and vulnerabilities

4 days


WEP security study (Continued)

WEP key cracking

1 week

Cisco LEAP Study and Testing


VPN Approach Study and Testing


SSL Approach Study and Testing


Aggregation and Analysis of Research results


Writing of the Master Thesis

Table 2. Tentative Thesis Timeline


(L. Goldberg, (1995), (D. L. Lough, Tutorial on Wireless LANs and IEEE 802. 11, "Virginia Polytechnic Institute and State University.

Randall K. Nichols, Panos C. Lekkas, (2001). Wireless Security Models, Threats, and Solutions.

Thomas M. Thomas (2004), Wireless Security By Sample Chapter is provided courtesy of Cisco Press.

(Theodore S. Rappaport, Wireless Communications, Principles and Practice, Prentice Hall, 1996. W. Stallings, Wireless Communications & Networks). http://www.securitymagazine.com/CDA/ArticleInformation/features/BNP__Features__Item/0,5411,77206,00.html

Interlink Networks, "Introduction to 802.1X for Wireless Local Area Networks", White Papers at Interlink Networks Resource Library, 2002. http://www.interlinknetworks.com/images/resource/802_1X_for_Wireless_LAN.pdf.

Interlink Networks, "Wireless LAN Security using Interlink Networks RAD Series AAA Server and Cisco EAP-LEAP", Application Notes at Interlink Networks Resource Library, 2002 http://interlinknetworks.com/images/resource/wireless_lan_security.pdf.

Jean-Paul Saindon, "Techniques to resolve 802.11 and wireless LAN technology in outdoor environments", News Article at SecurityMagazine.com, Aug 08 2002.

Jesse R.Walker, "Unsafe at any key size; An analysis of the WEP encapsulation", 802.11 Security Papers at NetSys.com, Oct 27 2000 http://www.netsys.com/library/papers/walker-2000-10-27.pdf

John Vollbrecht, David Rago, and Robert Moskowitz. "Wireless LAN Access Control and Authentication", White Papers at Interlink Networks Resource Library,2001.http://www.interlinknetworks.com/images/resource/WLAN_Access_Control.pdf.

Pierre Trudeau, "Building Secure Wireless Local Area Networks", White Papers at Colubris.com, 2001 http://download.colubris.com/library/whitepapers/WP-010712-EN-01-00.pdf

WLAN Association, "Introduction to Wireless LANs", WLANA Resource Center, 1999, http://www.wlana.com/learn/intro.pdf

WLAN Association, "Wireless Networking Standards and Organizations", WLANA Resource Center, April 17 2002 http://www.wlana.com/pdf/wlan_standards_orgs.pdf

Woodward, A. 2005. 'Recommendations for wireless network security policy'. [Online] Microsoft Academic Research. Available at: http://scissec.scis.ecu.edu.au/anzsys08/proceedings/2005/aism/woodward.pdf [Accessed: 13may2010].