By Galen Gruman, editorial director, IT Wireless
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Second Wireless Wave for Public Safety
Public safety departments primarily police and fire departments were among the early adopters of mobile wireless technology, using cellular networks from Motorola and the wireless phone carriers to transmit basic text messages to look up drivers' licenses and other basic data on suspects. In fact, such deployments have become commonplace, thanks to a steady stream of grants to local agencies from the U.S. Justice Dept. and others. Now, several years later, a second wave of public-safety deployments is occurring, this time bringing in 802.11 technology.
The use of 802.11 is a major development, since the technology has been mainly used for in-or-near-the-building deployments, not for wide-ranging areas such as cities and counties. But several factors are making 802.11 a part of these large-area networks: One is the high cost of cellular services, both legacy ones such as CDPD and new ones such as CDMA2000 and GPRS. The second is the improvement in 802.11 range thanks to better antennas and radios. Third, better routers, gateways, and switches let wireless networks integrate into wired networks without compromising traffic or security.
Consider two examples of such second-wave deployments: Post Falls, Ida., and Oakland, Calif.
Oakland: Migrating to 802.11
Oakland's experience is the most typical, and variations of it are playing out throughout the U.S. Several years ago, the Oakland PD implemented wireless messaging in 35 patrol motorcycles using CDPD technology, which operates at speeds of 9.6Kbps, or a fifth of what PC modems deliver. It's fine for exchanging basic text messages with dispatch and is more convenient and accurate than using over-the-air radio, which can also be picked up by police scanners and overheard by passengers in the police cars. But AT&T Wireless recently stopped supporting its CDPD network, leaving Oakland in the lurch. Although another provider is managing the network, Oakland PD decided to rethink its wireless strategy. In 1995, it deployed Motorola's proprietary RDLAP analog cellular technology (which has two channels of 19.2Kbps service) in police patrol cars, to avoid the monthly $50-per-vehicle CDPD fees and to gain network redundancy in case of outages, but it didn't want to invest more in such old technology when it got a grant in 2000 for wireless upgrades, says Lt. Inez Ramirez, the officer in charge of the wireless deployment.
That was two years ago. Today, Oakland PD is using its upgrade grant to add 802.11 wireless access. "We decided to leverage newer technologies," Ramirez says. The department has added wireless access to the laptops in the patrol cars and set up four hot spots: two at the police administration building, where the patrol cars are stored, one at an east Oakland substation, and one at an animal shelter across the street from a central Oakland substation. When the cars are started, they automatically synchronize with the network, downloading case files and other information to the notebooks. Police officers can synchronize the data while driving, as long as they're near one of the four hot spots.
When the cars are outside the 11Mbps 802.11 hot
spots, they are automatically switched to RDLAP or CDPD. No login is
required. Each patrol car has a dedicated IP address, so the Padcom
TotalRoam routing software can easily track which network the cars are on
and switch them seamlessly from one network to another. Padcom also helped
modify the XcelleNet software that does file synchronization to make it
work automatically when the cars start up and to suspend downloads and
uploads when the cars are out of 802.11 range. Ramirez says the patrol
cars have 802.11 access in a two-block radius, which gives them
flexibility in how and where to approach the access points. All four
access points should be live this summer; the two at the police
administration building are already up and
The next step may be to install 802.11 access points at the city's 35 fire stations. Because they are placed evenly throughout the city of 400,000 near San Francisco, they would give broad coverage to patrol cars as well, Ramirez says. But before committing to the fire station deployment, Ramirez wants to make security "really, really tight." He's not concerned about people intercepting transmissions from or to patrol cars the data is short and intermittent, so the combination of MAC address filtering, Wireless Equivalency Protocol (WEP), and client/server encryption safeguards that data. Instead, Ramirez wants to make sure people can't tap into the police department's wired network or into other city networks through the fire stations. So he's looking at installing firewalls at each access point, as well as Cisco Systems' own security tools (the department is standardizing on Cisco access points).
Post Falls: All 802.11, Everywhere
Unlike Oakland PD's Ramirez, Lt. Scot Hoag of the Post Falls PD didn't have a legacy wireless system. There was no CDPD service in the town of 20,000 right across the state line from Spokane, Wash. But when the city got a grant in fall 2001 to deploy a wireless system, the Post Falls PD decided to go all-802.11 rather than use the GPRS cellular service that recently became available. "Our intention was to go with GPRS, but the cellular carriers were unable to provide an all-you-can-eat plan we could afford," he says.
Instead, the city has covered more than 50 square miles with 802.11b access point providing 90% availability, Hoag says. The system uses 23 access points placed on light poles, along the highway, on mountain peaks, on water tanks, and colocated on cell-phone towers. Using a combination of unidirectional and omnidirectional antennas and amplifiers, most of the access points have a five-mile range, he notes.
With an all-802.11 network, Hoag has a lot of bandwidth to exploit, so he's implementing voice-over-IP, email, and video cameras over the network in the 22 patrol cars used by 31 officers. For example, officers can control security cameras at various locations in the city to focus on specific areas, watching the video on their laptops. "Our goals were to have all this stuff in the cars," he says. "The wireless network becomes an extension of the wired network." Although those using the voice-over-IP system to talk to dispatch notice some degradation when switching from one access point to another, "it's pretty transparent" for the other uses, Hoag says.
Of the $208,000 spent on the wireless system, a quarter of the money went to security, Hoag says. The Post Falls PD enabled all the built-in encryption, including WEP, and is using 128-bit software encryption using an algorithm of the department's own choosing, dynamically rotating keys, proprietary compression, and 802.1x authentication. "I'm about 98% happy with the security of this system," says Mel Nottage, whose Network Group consultancy helped deploy the systems. Nottage further notes, "I'm never 100% happy." Like other police systems, the Post Falls PD laptops all have fixed IP addresses. The department uses NetMotion Wireless's Mobility management and security suite to handle the roaming between access points (with no need to log in again) and to handle the security. NetMotion Mobility also resumes any interrupted session, rather than require data to be resent or sessions be reinitialized.
The biggest security concern is that others will tap into the network to access police and city systems or simply to tap into a free citywide network, which could lead to congestion issues that interferes with police access, Hoag says.
Hoag is also not worried about a system that has limited geographic reach. "The only time we'd go outside the city is for a pursuit or for a meeting," he says, "and we keep a few cell phones for that."
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WIRELESS PRODUCT AND SERVICE GUIDE!
A subscriber exclusive! IT Wireless's Winter 2003 Essential Products Guide is now available to subscribers. The 10-page PDF file contains a listing of key vendors and service providers, with summaries of their offerings and contact information. Categories include wireless network and client hardware, network and client software, and IT services. Download the directory now!
WIRELESS PRODUCT AND SERVICE GUIDE!
Parker Hannifin has demonstrated several wireless applications for industrial environments. The Bluetooth-based products include hydraulic system wireless diagnostics and process valve diagnostics and controls.
Vaultus has released its Mobile Application Framework, which helps enterprise IT developers develop mobile versions of their business applications for use on PDAs, as well as permitting wireless synchronization. A connector for SalesLogix is now available, and connectors for J.D. Edwards, Onyx, SAP, PeopleSoft, and Siebel are planned.
Nortel Networks plans to release by July a suite of tools for enterprises to implement wireless access: the Nortel WLAN Security Switch, WLAN Access Point, WLAN Mobile Adapter, and WLAN Mobile Voice Client. These products support 802.11a and 802.11b.
Venturi Wireless is offering the Venturi100e wireless accelerators for enterprises. By using a burst mode, the company says it can deliver cellular data speeds of 100Kbps, about five times that of standard connections, for Microsoft Exchange email servers using virtual private networks from Nortel, Cisco, and Checkpoint.
Symbol Technologies has integrated the Federal Information Processing Standard for cryptography (FIPS 140-2) into the AirBeam Safe virtual private network (VPN) client software for its line of rugged, wireless mobile computing devices. FIPS 140-2 is meant to protect "sensitive but unclassified data" in mobile computing applications deployed for federal government and civilian agency customers. Meanwhile, Research in Motion has received FIPS certification for its BlackBerry messaging devices and network, including FIPS 140-2 validation for its Java-based devices.
Intermec Technologies has released the CT60, a tablet PC with wireless access. Offering the same PC architecture and Windows operating system as other makers' tablets, the CT60 features a rugged design to withstand freezing temperatures, rain, and other adverse conditions. Intermec specializes in field-force devices.
SonicWall has announced the $895 SOHO TZW wired-to-wireless LAN bridge for small businesses. It provides IPSec authentication and encryption on virtual private networks and enforces security policies on client systems. It also provides a guest zone for public areas that let visitors access the Internet but not corporate networks. The base model supports 25 users and is expandable.
IPWireless has added voice-over-IP and "push-to-talk" walkie-talkie features to its high-speed cellular data technology, which is deployed in several U.S. and overseas locations as an alternative to slower CDMA2000 and GPRS networks provided by the major cellular carriers. A variation of the UMTS third-generation (3G) cellular technology, it offers connections speeds of up to 2MBps.
Mobility Network Systems has released client roaming software that authenticates users against the Subscriber Identity Module (SIM) card in their wireless modem. GPRS carriers use SIM cards in their cellular phones to authenticate users, and the Mobility software lets notebooks with SIM-equipped PC Cards (such as the Sierra Wireless AirCard 750) authenticate themselves on 802.11 networks. This should let cellular carriers offer automatic authenticated 802.11 access as well as GPRS access on one account.
Engim has released its EN-3000 chips, which will let access points based on them simultaneously communicate on multiple channels each of 802.11 a and b/g. This will make voice-over-wireless-IP (VoWIP) connections more stable, reducing dropouts during conversations. As yet, no access point makers have signed up to use the chips.
Got a great product or technology tip? Send it to email@example.com.
Several companies have joined the WiMax Forum, an industry association that aims to certify interoperability around the IEEE 802.16a standard for broadband wireless connections used in metropolitan area networks, such as those that connect 802.11 hot spots. The IEEE modified the standard in January to extend it to the 2GHz-to-11GHz frequencies. An 802.16 network can connect 802.11 hot spots to the Internet and provide a wireless extension to cable and DSL for last-mile broadband access. It provides up to 31 miles of linear service area range and provides users broadband connectivity without needing a direct line of sight to the base station. The wireless broadband technology also provides shared data rates up to 70Mbps, which is enough bandwidth to simultaneously support more than 60 businesses with T1-type connectivity and hundreds of homes with DSL-type connectivity using a single sector of a base station. A typical base station has up to six sectors. WiMax's members now include Airspan Networks, Alvarion, Aperto Networks, Ensemble Communications, Fujitsu Microelectronics America, Intel, Nokia, the OFDM Forum, Proxim, and Wi-LAN. (The OFDM Forum is an industry association centered around orthogonal frequency division multiplexing technology, which is a way of sending 802.11 signals over greater distances than traditional radios.)
In other market trends, there were several more signs recently of 802.11's growing popularity for business travelers:
From IT Wireless
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