1. B, D. A device driver allows the computer operating system to control the wireless network adapter and must be installed in order for the adapter to function. Client utility software allows a user to configure the adapter with network specific settings such as the SSID and security settings. Client utility software may be part of the computer operating system or third-party software provided by the manufacturer of the adapter. Site survey software and signal strength software may be part of the client utility software. AutoConfig is a service that runs on a Microsoft Windows 7 computer. See Chapter 4 for more information.

2. C. The Network layer is responsible for addressing and routing of frames and is where IP addresses are used. The Data Link layer of the OSI model is responsible for compiling or packaging bits into frames. The Physical layer allows frames to be sent and received across a medium. The Transport layer is responsible for connection-oriented or connectionless protocols, and the Application layer is the “interface to the user.” For more information, see Chapter 1.

3. D. Local regulatory authorities manage the RF spectrum used in both unlicensed and licensed applications. The IEEE creates standards and the Wi-Fi Alliance certifies devices for interoperability. Wireless Ethernet Compatibility Alliance is the former name of the Wi-Fi Alliance. For more information, see Chapter 2.

4. B. In a full mesh network, all nodes connect together with at least two paths for every node. This technology is on the increase in outdoor installations and starting to appear in indoor installations as well. It is common in metropolitan area networks and campus area networks. Many access points and wireless LAN switches/controllers have the capability built in. For more information, see Chapter 3.

5. A. A wireless repeater—which in most cases is a function of an access point—will extend the RF cell to allow users at a greater distance to connect. This will have an impact on throughput for users connected to the repeater and this solution is recommended only when necessary. For more information, see Chapter 3.

6. A. Some wireless personal networks (WPANs), such as Bluetooth, use FHSS for communications. This will potentially interfere with IEEE 802.11 wireless networks. DSSS, HR/DSSS, and ERP-OFDM are all used in wireless LANs. HR/FHSS does not exist. For more information, see Chapter 5.

7. A, D. Passive and active are the two modes in which a manual site survey can be performed. Passive mode monitors all RF, and active mode requires a client association. For more information, see Chapter 11.

8. C. Third-party client utilities such as Microsoft's WZC can be used in either SOHO or enterprise implementations. Because this utility is built into the Microsoft Windows operating system, it is very common in both types of installations. See Chapter 4 for more information.

9. A, B, C. The number of users, applications both hardware and software, and other IEEE 802.11 wireless networks are technical areas that must be known for a new IEEE 802.11 wireless LAN installation. The cost of the equipment does not fall under the technical category. For more information, see Chapter 10.

10. A. Most manufacturers that offer utilities for wireless LAN adapters allow for additional configuration above and beyond the settings that are included with an operating system. Manufacturer utilities are not required for the adapter to operate, because some settings can be made in the device driver or a third-party client utility. Unless it is specialty client software, the utility is usually included with the adapter and is not subject to additional fee. Manufacturers' client software utilities are unique to only those adapters and will not work across manufacturers. See Chapter 4 for more information.

11. A. An independent basic service set (IBSS) is an ad hoc network that is used for peer-to-peer communications. No access points are used in an IBSS implementation. For more information, see Chapter 8.

12. E. An omnidirectional antenna has a horizontal radiation pattern of 360 degrees. The vertical radiation pattern will vary based on the gain of the antenna. This measurement is known as the beamwidth and is used for both horizontal and vertical radiation patterns. Beamwidth is measured at the –3dB or half-power point. For more information, see Chapter 7.

13. E. 802.11n and MIMO commonly use up to three radios in either the 2.4 GHz ISM or the 5 GHz UNII band. 802.11a/g uses one radio per band but can use two antennas for diversity. 802.11h is for spectrum management. For more information, see Chapter 5.

14. C. The IEEE 802.11g amendment to the standard and the 802.11a amendment both support up to 54 Mbps maximum data rates. However, of the two, only 802.11g operates in the 2.4 GHz ISM band. 802.11b also operates in the 2.4 GHz ISM band but only supports a maximum data rate of 11 Mbps. The IEEE 802.11n amendment allows support of up to 600 Mbps. For more information, see Chapter 2.

15. D. Both DSSS and HR/DSSS channels are 22 MHz wide. 2.412 GHz and 5.160 GHz is the center frequency of some channels used. For more information, see Chapter 5.

16. B. IEEE 802.11g networks operate in the 2.4 GHz ISM band. 802.11a networks operate in the 5 GHz UNII bands and in the United States the 5.725–5.875 GHz ISM band. IEEE standards-based wireless networks do not use the 900 MHz ISM band. For more information, see Chapter 6.

17. A. A local area network (LAN) is usually contained in the same physical area and usually is bounded by the perimeter of a building. A campus area network (CAN) includes a set of interconnected LANs within an office or school campus and is usually within a limited geographical area. A wide area network (WAN) mostly consists of point-to-point or point-to-multipoint connections between two or more LANs and a metropolitan area network (MAN) consists of networks that may span from several blocks of buildings to entire cities. For more information, see Chapter 1.

18. A, D, G. SSID hiding, WEP, and MAC filtering are legacy security mechanisms for IEEE 802.11 wireless networks and should not be used. WPA and WPA 2.0 are Wi-Fi certifications and are more advanced. Virtual private network (VPN) is a Layer 3 security solution typically used for remote access. RBAC is role-based access control. For more information, see Chapter 9.

19. C, F. In the 2.4 GHz ISM band, 25 MHz or 5 channels of separation is considered non-overlapping. Based on the IEEE 802.11-2012 Standard Clause 18, HR/DSSS channels must be separated by 25 MHz or greater in order to be considered non-overlapping. For more information, see Chapter 6.

20. C. The number of associated users will affect the capacity of an access point. The frequency range will affect the propagation as well as the output power. Reflections will cause multipath. For more information, see Chapter 6.

21. B. Low throughput may occur when too many client devices are associated to an access point and cause overloading. Load balancing would help to solve this problem. Because of DRS, the closer the client device is to an access point, the better the throughput. For more information, see Chapter 12.

22. B. An impedance mismatch between connections in a WLAN system will cause VSWR. The gain of an antenna is a relative value that has to do with the size or shape of the RF pattern emitted. Attenuation of cable adds to the overall loss of the system. For more information, see Chapter 7.

23. D. Open system authentication is addressed in the IEEE original 802.11 standard and allows a wireless client device to 802.11 authenticate to an access point in order to 802.11 associate. Shared key authentication is legacy and flawed and either cannot or should not be used. Open system authentication is a “null” authentication, is automatic and not secure. For more information, see Chapter 8.

24. A. The SSID is the name that identifies a wireless network. The MAC address of the access point radio is the BSSID. For more information, see Chapter 8.

25. B. 802.1X is for port-based access control and the terminology for the access point is authenticator. The RADIUS server is the authentication server and the client device is a supplicant. The RAS server is the predecessor to RADIUS. For more information, see Chapter 9.

26. C. A virtual private network (VPN) solution is a Layer 3 (Network) VPN security solution and is commonly used for remote access connectivity from unsecured networks such as hotspots. For more information, see Chapter 9.

27. B. A predictive analysis site survey will minimize the time required on-site for testing and analysis. This site survey will be accurate if the information about the location input is accurate. A manual site survey requires a walkthrough of the area and can be time consuming. For more information, see Chapter 11.

28. B, D. The number of devices is an important determining factor in the number of access points required for a wireless LAN deployment as well as the software and hardware applications that may be used. The type and manufacturer of devices are not concerns. For more information, see Chapter 10.

29. C. A protocol analyzer will help identify existing wireless networks in an area and provide other information about these networks that can be used in the site survey/design process. An RF analysis is performed by a spectrum analyzer, which will also help locate sources of RF interference. A protocol analyzer can help identify security-related issues from existing wireless networks but will not describe security requirements of a new wireless LAN. For more information, see Chapter 11.

30. A. The received signal strength represents how much of a transmitted signal is being received. If this signal is weak, the difference between the signal and noise may not be high enough to recover the data. If the power on an access point is high, it would provide more received signal. A signal-to-noise ratio of 35 dB is more than adequate. If the radio on the client was disabled, it would not be able to connect at all. For more information, see Chapter 12.

31. A, B, D. Wireless LAN technology operates and is specified at layers 1 (Physical) and 2 (Data Link) of the OSI model. The Session layer opens, closes, and manages sessions between end-user application processes. The Network layer is responsible for addressing and routing functions of data and the Application layer is the interface to the user. For more information, see Chapter 1.

32. A, E. The signal to noise ratio is the difference between the received signal and the noise floor. The common noise floor value is –95 dBm, and an acceptable receive signal is –65 dBm. Therefore the signal to noise ratio is 30 dBm. The RF channel is a specified frequency a WLAN operates in. The Fresnel zone consists of a number of concentric ellipsoidal volumes that surround the direct, RF line of sight between two points such as an RF transmitter and receiver. For more information, see Chapter 6.

33. A. Most enterprise-level autonomous access points have the capability to operate in root, repeater, or bridge modes. Root mode is the most common. Root mode allows devices to authenticate, associate, and access network resources and services. For more information, see Chapter 3.

34. E. Wi-Fi Protected Access 2 (WPA 2.0) requires CCMP/AES. TKIP/RC4 is optional. WEP/RC4 is legacy and should not be used. It cannot be used with a robust secure network. RC5 is a stream cipher and not used with IEEE 802.11 wireless LANs. CCMP uses AES, not RC4. For more information, see Chapter 2.

35. D. CSMA/CA stands for Carrier Sense Multiple Access/Collision Avoidance and is used as an access method for wireless LANs to share the communication medium, which is the air. CSMA/CD is Carrier Sense Multiple Access Collision/Detection Avoidance and is used with Ethernet networks. FHSS and HR/DSSS are spread-spectrum technologies used with some standards or amendments. CSMA/DSSS does not exist. For more information, see Chapter 5.

36. B. The technical term for the horizontal radiation pattern is azimuth. The elevation is the vertical radiation pattern. For more information, see Chapter 7.

37. B. A beacon frame is a management frame and is used to advertise information about the wireless LAN. For more information, see Chapter 8.