Wireless Data Communications

• Wireless LANs at UC
• How to obtain a wireless installation
• Standard for wireless installations
• Guidelines for the Use of the 2.4 GHz Radio Frequencies
• Tested wireless cards
• How to register your wireless card
• Current wireless locations on campus
• Support provided by UCit for wireless installations
• University training and resources
• Changes to Wireless LAN Access on Campus

WIRELESS LANS AT UC

The current wireless LAN environment at UC is 802.11b and 802.11g compliant. Migration has begun to 802.11g wireless access points which will support 802.11b cards as well as the 802.11g cards. The 802.11b standard allows for data transmission between the workstation and wireless access points at 11MB. When signal strength diminishes due to distance between the workstation and access point, speeds of 5.5MB, 2MB and 1MB are also supported. The 802.11g standard allows data transmission between the workstation and wireless access point at 54MB. When signal strength diminishes due to distance between the workstation and access point, speeds of 48MB, 36MB, 24MB, 18MB, 12MB, 11MB, 9MB, 6MB, 5.5MB, 2MB AND 1MB are also supported. Note that 802.11g access points will support 802.11b equipped workstations, but only at 802.11b speeds. The access point connects to the UC network via 10/100MB Ethernet. See CURRENT WIRELESS LOCATIONS ON CAMPUS for a list of access point locations on campus.

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HOW TO OBTAIN A WIRELESS INSTALLATION

Complete a request through GETit for a wireless installation cost estimate, UCit will perform a site survey to determine the number and placement of wireless access points, antenna types, etc. In order to provide an accurate cost estimate and provide optimum performance for your area, UCit will need to know the exact area(s) that is/are desired to be covered as well as the estimated number of simultaneous users within each area(s). For example, a "normal" installation in a classroom with one Access Point would cost approximately $1,200. This includes UCit site survey, access point, antenna, "normal" data jack installation and access point configuration and "normal" installation. Building construction may have an impact on the installation costs, and can only be accurately estimated after the site survey. Any external installation requiring conduit runs will need to have a cost estimate for the conduit installation from the UC electricians. There is an additional $69 per month ongoing charge for the switch port to which the access point is connected.

It should be noted that a standard has been set for wireless installations on campus as well as channel assignments for the wireless access points. In order to avoid interference between access points and possible incompatibilities, UCit must coordinate all wireless installations, whether installed by UCit or the department. UCit is only capable of supporting and trouble shooting wireless hardware that is listed in the standards document. It should be noted that 802.11g hardware is being phased in to replace the current 802.11b equipment. All future access point installations will be of the 802.11g type. See sections 8.1.6 and 13.9.1 for more details on supported hardware.

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STANDARD FOR WIRELESS INSTALLATIONS

UCit has developed a set of standards for the deployment of Wireless LANs on all UC campuses. These standards will continue to evolve as the Wireless LAN products evolve. We will update this standard periodically until the technology and market is stable. These standards are intended to:

• Provide information and guidance to University LAN Administrators who wish to deploy departmental wireless LANs.
• Allow for maximum possible flexibility and enable UCit to provide campus-wide wireless infrastructure.
• Prevent conflicts in frequency usage between departments.
• Allow for roaming within buildings without loss of signal.
• Prevent unauthorized access to campus and departmental LANs.
• Make use of common standards to maximize product choices and supported platforms.

All wireless LAN installations on the UC campuses must be coordinated by UCit Network & Telecom Services. The following standards must be adhered to for all IEEE 802.11b/g compliant wireless LAN installations.

1. HARDWARE

At this point in time, the access points must be Cisco Aironet 1200 Series Access Points. The part number is AIR-AP1231G-A-K9. A power cord (AIR-PWR-CORD-NA) and power injector (AIR-PWRINJ3) are also required.

All new PCMCIA cards must support 128 bit encryption and open authentication, with the recommended card being the Cisco Aironet 350 Series Client Adapter part number AIR-PCM352. UCit has tested 128 bit cards from Linksys, 3Com, Orinoco (Lucent) and Dell and found that they function properly with the Cisco access points. Apple Airport cards for MacIntosh computers with Version 2.0 or later Airport software should also function properly with Cisco access points. There are many other 802.11b and 802.11g cards on the market. Due to limited resources, UCit can only support the cards that have been tested. Support for other cards must be obtained from the manufacturer or from your departmental IT support group, where applicable.

There are many brands and types of external antennas available for use with the access points. Antennas from Centurion are recommended by UCit and the commonly used types are as follows.

Antenna extension cables 25 feet or longer must be constructed using LMR-600 coax cable. Cables less than 30 feet may be constructed using either LMR-600 or LMR-400 cable. Following are the part numbers for some extension cables.

2. AUTHENTICATION

All access points will authenticate all users using the UCit wireless RADIUS servers. The primary server's address is 10.25.5.247 with authentication port set to 1812. The secondary server's address is 10.25.9.247 with authentication port set to 1812. The userid is the hex MAC address of the PCMCIA card, e.g. 000000000000. The password is also the MAC address.

3. DHCP

All wireless users will obtain their IP address dynamically. UCit requires that the access points be set to pass DHCP requests to the central UC DHCP servers. To connect to a wireless access point and obtain an IP address via DHCP, the users MAC address must be registered in the RADIUS database. This can be easily accomplished via a web page.

4. ENCRYPTION

Wireless encryption provides "Wire Equivalent Protection" (WEP) for transmitted data. All wireless transmissions will be encrypted using 128 bit encryption. All access points will transmit using 128 bit transmissions. Encryption key and SSID to be used will be given to the user during the web MAC address registration process.

5. ACCESS POINT PASSWORD

The access point read write password must be changed from the factory default on all access points. UCit will assign and maintain the passwords. In certain cases, departmental IT personnel may be granted read privileges to access point log information.

6. CHANNEL ASSIGNMENTS

The 802.11b and 802.11g specifications provide 11 channels, but these overlap, so at most three channels can be used in the same space. On UC campuses, channels 1, 6, and 11 will be used and will be assigned to access points by UCit. Channels other than 1, 6, and 11 should not be used at the University, as they mightinterfere with compliant infrastructure.

7. SSID

All access points' SSIDs must be configured such that user's can configure their cards to access all UC access points. UCit will supply users with the SSID for UC when they successfully register their wireless card.

8. RECOMMENDATIONS

• Complete a request through GETit to have UCit perform a comprehensive site survey
  
  Wireless LANs are limited in speed, bandwidth and coverage. The 11Mbps or 54Mbps speed of an 802.11b or 802.11g LAN is the total speed of all users sharing the same access point. A site survey will help to estimate the number of access points needed to cover the desired area at a given level of performance. Optimum access point location and antenna type can only be determined by a comprehensive site survey.
  
  
• Compliment the wired infrastructure
  
  Where possible, the use of a hard wired connection is preferred because it is faster and easier to expand and does not take bandwidth from other wireless stations. Wireless LANs should not be used instead of hard wired jacks in offices, classroom instructor locations, computer labs, etc. Wireless LANs are practical for areas such as outside open spaces, study areas, large auditorium type classrooms, meeting rooms and conference centers. Given the current lack of maturity of the wireless technology and security features, it cannot be considered a production university service at this time. Therefore UCit recommends that users currently only deploy the technology to support non-critical business functions.

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GUIDELINES FOR THE USE OF THE 2.4 GHz RADIO FREQUENCIES

University of Cincinnati Information Technologies (UCit) has been given primary responsibility for the design, installation, and operation of the wireless network environment on the UC Campus. This system will allow campus users to access all campus information technology resources from mobile or portable computers. However, in order to achieve a robust and stable wireless infrastructure and prevent unintended interference to FCC licensed services, UCit must maintain administrative control of the radio frequency spectrum that wireless devices utilize as their base transport mechanism.

802.11b and 802.11g wireless local area networking use the FCC unlicensed 2.4 GHz Industrial, Scientific, Medical (ISM) band. Certain other "wireless" devices exist in the market place that also employ the same 2.4 GHz frequency band and can cause interference to users of the wireless service. These devices include, but are not limited to other wireless LAN devices, cordless telephones, cameras, and audio speakers.

In order to assure the highest level of service to the users of wireless network, UCit needs help from all members of the campus community in minimizing the potential interference from those devices. UCit requests that use of all other 2.4 devices be discontinued in university-owned buildings. In cases where the device is being used for a specific teaching or research application, UCit requests that the college, department, researcher or faculty member work with UCit to determine the priority and whether there are circumstances under which use of the device may still be accommodated without causing interference to the installed wireless community. Through channel frequency coordination with UCit, it is possible that most devices operating in the same frequency ranges can be accommodated on campus in fixed locations. Where interference issues cannot be resolved working with UCit, the college and Provost offices will determine the priority. UCit's role is to assist those involved by providing the options available for resolution of the interference issues in such cases.

UCit will approach the shared use of the 2.4 GHz radio frequency in the same way that it manages the shared use of the wired network. While it will not actively monitor use of the airspace for potential interfering devices, we will seek out the user of a specific device should we find it causing harmful interference to the campus network or other FCC licensed service. In these cases, UCit reserves the right to restrict the use of all FCC licensed Part 15 ISM and U-NII devices in university-owned buildings and all outdoor spaces on the UC Main Campus. See the UC General Policy on the Use of Information Technology for information on the campus computing policies, including those related to responsible use of shared resources, such as the campus airspace in this case.

If you think you have an existing system that may use 2.4 GHz radios for transmission or you are planning to purchase a wireless system and you are uncertain if it employs 2.4 GHz radios, please contact the UCit Help Desk at 556-3785 or send mail to noc@uc.edu. The Help Desk can assist in determining if such devices will cause interference to the wireless network.

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TESTED WIRELESS CARDS

UCit has tested and found several wireless LAN 802.11b and 802.11g standard PCMCIA cards, which are compatible with the UC standard wireless LAN access points. This list should not be considered to be the all inclusive list of cards which will function properly with the UC wireless LAN access points. The list contains only the cards which UCit has tested to date and will support. All compatible cards must support 128 bit encryption and open authentication. PCI and ISA cards from the same manufacturer should also be compatible, although not tested by UCit. Cards, which are not on the list, will not be supported by UCit. Support for these should be obtained from the manufacturer or other source. This list will be updated as others are tested.

Cisco/Aironet 350 series cards and adapters

UCit recommends that you download the latest version of the software for the Cisco 340 and 350 series cards, instead of using the software on the CD that comes with the card. Go to page http://www.cisco.com/public/sw-center/sw-wireless.shtml. Follow the instructions on the Release Notes for installation. Set the SSID and WEP keys as instructed when you register your card. Additional configuration help can be found at the College of Engineering help page.

Linksys b, g and a+g cards

WaveLAN/Orinoco Gold Cards

3Com

Dell supplied 128 bit cards from Cisco/Aironet, Intel and Orinoco

UCit currently recommends the Cisco 350 series, Linksys, or Dell supplied cards and provides complete support for them. Other cards listed above will be supported on a best effort basis only. Cards not listed above will not be supported by UCit

Consult the user’s guide for your particular card for information on how to set the SSID, open authentication WEP encryption key to meet UC requirements.

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HOW TO REGISTER YOUR WIRELESS CARD

In order to use the UC wireless LAN, your wireless card must be registered in the authentication database. To register a card, you must be a currently registered student or a current faculty or staff member. To register your card you will need the ethernet MAC address which can be found on the back of most cards. After obtaining the MAC address, register your card. Any authorized user can register multiple cards if desired. When successfully registering your card, you will receive the WEP encryption key and SSID to be used at UC.

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CURRENT WIRELESS LOCATIONS ON CAMPUS

Wireless access points are currently installed in the locations listed below. For more detailed information including room numbers see our expanded list.

(w) = West Campus Map     (e) = East Campus Map

(w) = West Campus Map     (e) = East Campus Map

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SUPPORT PROVIDED BY UCit FOR INSTALLED WIRELESS LOCATIONS

UCit supports the technology required for wireless installations. However, users should note that this technology is not as mature or fault tolerant as the equipment used with the wired network. Users are advised to take this into consideration when determining which solution is best to meet their business needs.

UCit is evaluating wireless network management tools to improve the level of support to the wireless infrastructure. The potential benefits of these emerging tools are as follows:

• Reduces deployment and operating expense
• Simplifies daily operation and management of medium and large scale wireless LANs
• Enhances security by detecting, locating and mitigating rogue access points, by ensuring consistent application of security policies, and by monitoring 802.1X performance
• Improves WLAN performance and availability by detecting RF interference and by monitoring faults
• Saves time and resources by automating and centralizing repetitive, time-consuming management tasks

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UNIVERSITY TRAINING AND RESOURCES

The College of Engineering has a web page for help in setting up a wireless card.

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