Technology cuts Wi-Fi interference
As Wi-Fi access points proliferate at an accelerated rate, the technology itself is facing two major challenges: lack of throughput and interference. A Scottsdale, Ariz., start-up claims it has developed a next-generation Wi-Fi access point technology that makes any 802.11-based wireless LAN interference-resistant.
Founded in 2003, Rotani recently came out of stealth mode to offer the AirReferee, a turnkey access point reference design that provides the uninterrupted throughput necessary for multiple video streams, online gaming, voice over IP and other latency-and throughput-sensitive applications. According to the company, AirReferee improves 802.11a/b/g product performance by eight times in real-world conditions without having to replace any existing hardware.
Rotani’s own offices serve as a demonstration center where the company runs four DVD-quality videos simultaneously despite the fact that it is surrounded by 17 other access points.
“When you walk away from an access point, the throughput falls dramatically. What we focused on was not how to extend the range but how to preserve higher bandwidth,” said Roc Lastinger, Rotani’s president and chief technology officer. “We’re talking about standard off-the-shelf radios, and we’ve combined them with this antenna structure.”
Rotani’s AirReferee is essentially a low-cost version of multiple-input/multiple-output (MIMO) — smart antenna technology that will be the basis of the next generation of 802.11 technology, known as 802.11n, which proposes to increase the range, data speeds and reliability of Wi-Fi networks.
The AirReferee access point combines two standard off-the-shelf 802.11 radios with Rotani’s patent-pending antenna architecture. Each radio is attached to one or more directional antennas. The access point automatically scans the environment and optimally configures the channel assignment for each radio/antenna to minimally interfere with adjacent wireless networks. The result is a significant noise reduction, Lastinger said.
Under international regulation, only three independent channels are available for 2.4 GHz WLAN systems. With an extended range of 300 feet and a limited number of independent channels, only a small number of wireless networks can coexist, according to the company. In short, 802.11 wireless networks were never designed for dense urban environments.
“Our antennas cost the same as a whip antenna,” Lastinger said. “It is a very low-cost implementation of MIMO because we are using two radios, and we hook that to low-cost internal architecture, and we aren’t using beam-forming technology.”
Lastinger is reluctant to label the AirReferee as MIMO technology because Wi-Fi vendors are offering the market a host of pre-standardized 802.11n products, all based on various flavors of MIMO.
“I’m not going to release a MIMO product until there is a standard,” Lastinger said. “We’ve been working to have multiple MIMO radios.”
Rotani’s initial target market is the telco industry, but its technology could be applicable to any entity deploying Wi-Fi. With six full-time employees, the company is working with OEMs and is in discussions with radio manufacturers looking to include AirReferee in their next-generation designs.
“We’re giving more life to the [802.11]g standard,” Lastinger said. “Telcos have been floored with the ability to maintain the video link.”
Nextel Communications has added Motorola’s i760 to its handset suite. The GPS-enabled i760 lets users communicate via the carrier’s Direct Connect and Group Connect walkie-talkie services as well as via digital cellular phone service and text messaging. Nextel also is offering the i560, a handset that meets military standards for dust, shock, vibration, temperature extremes, low pressure and solar radiation. In addition to the P2T capabilities offered by the i760, the i560 handset also offers Nextel’s Direct Talk service, which provides short-range walkie-talkie service in areas without network coverage.
4.9 GHz video surveillance system
Motorola’s Intelligent Video Surveillance and Control solution rides over the company’s 4.9 GHz mesh network and is capable of recognizing unusual events based on parameters set by dispatchers. The system provides alerts in the form of green and red circles that appear on a dispatcher’s screen around questionable people or things.
The system is designed to help dispatchers monitoring multiple screens make better decisions. The video seen by the dispatcher also could be transmitted to in-vehicle laptops over the 4.9 GHz network to make first responders safer and more effective.
Motorola also it has begun initial deployments of infrastructure that will let its Astro 25 customers realize a tenfold increase in the data rates inherent in the system. Currently, a standard Astro 25 provides customers with a data rate of 9.6 kb/s on a standard 25 KHz channel. Those customers can reach data rates of 96 kb/s simply by investing in another base station at each tower site of the 800 MHz network, the company said.
P25 migration solution
Icom’s three-tier suite of mobile and mobile radios is designed to ease the migration of public-safety agencies to APCO’s Project 25 digital standard. The F70 portables and F1720 mobiles each come in three versions. One is fully P25 compliant for agencies that already have made the transition; another is P25-upgradable with the use of optional firmware for agencies that are planning to migrate in the near future; and the third requires firmware and module options to bring them into P25 compliance, for agencies whose migration strategies are longer term.
Texas Instruments’ ADS5440 is a 13-bit, 210MSPS analog-to-digital converter that offers 68-decibel signal-to-noise ration, a 79-decibel spurious-free dynamic range — at the maximum sample rate of 210MSPS — and input frequency of 230 MHz. The unit is designed to improve receiver performance of software-defined radios, base station power amplifier linearization systems, and test and measurement systems. It operates from a 5V power supply and has an operating temperature range of -40° Celsius to 85° Celsius.
M/A-COM’s P7200 quad-mode radio supports the company’s OpenSky and EDACS IP-based platforms as well as APCO’s Project 25 digital standard — both conventional and trunking — and analog. The radio operates in the 700 MHz and 800 MHz bands. A UHF/VHF version also is available.
In addition, the company unveiled a hand-held application that lets Bluetooth-enabled devices such as PDAs communicate with remote servers via the OpenSky platform. When an officer in the field wants to make a request, he or she can use a Bluetooth-enabled PDA, which would connect to a Bluetooth-enabled OpenSky radio, which then transmits the request to the server. The report then is transmitted back to the hand-held device in the same manner.
Project 25 VHF radio
Kenwood’s TK-5710, mobile radio is designed for public-safety use and provides both conventional operations and Project 25 capability. In addition, the VHF radio also is compatible with Kenwood’s FleetSync platform — which provides enhanced messaging and automatic vehicle location capability — and offers AES/DES encryption options.
Other options include: three mounting configurations (dash mount, single or dual control head remote mounts); a choice of two front panels; a 12-character alphanumeric display with built-in speaker; or a 14-character alphanumeric display with an external speaker option. The TK-5710 also offers dual priority scan, 512 channels/50 zones, emergency call features and meets Mil Std 810 C, D, E & F.
P25 trunked repeater
EFJohnson introduced the 3800 Series Project 25 digital repeater. The repeater enables flexible frequency changes and provides an IP connection for efficient field upgrades and dispatch communications. It is a component of the company’s IP25 Trunked Infrastructure System, an encrypted end-to-end digital P25-compliant system that uses voice-over-IP technology to integrate repeaters, a digital dispatch console, system management, a secure key management facility for over-the-air re-keying of radios in the field and a portable PDA-based key loader.
Mesh-networking software suite
PacketHop announced the release of its first commercial products, which include Version 1.0 of its TrueMesh mobile mesh-networking software and its Aware for Public Safety applications suite. Unlike other mesh-networking solutions, PacketHop’s architecture enables multimedia communications via a variety of devices connected in an ad hoc mesh — typically linked in the 2.4 GHz unlicensed band — solely through software.
Although PacketHop has developed an application suite, Vice President of Marketing David Thompson said the company hopes to establish a developers’ group to let third-party developers create their own applications.
IP-based PSAP solution
CML Emergency Services introduced the first IP-based, 911 communications system certified by IP networking giant Cisco. The Patriot 3.0 solution, which integrates call handling and radio dispatch, is being deployed in a small PSAP in Cortez, Colo. Patriot 3.0 converges voice and data onto a single IP network and readies public-safety agencies for the integration of data streams of pictures, video, text and any future IP-based technologies.
MaxStream’s stand-alone XBee-PRO radio complies with both the ZigBee and 802.15.4 standards. The radio features an aluminum housing, a 2.1 dBi dipole antenna and either an RS-232 or USB connection port. The 2.4 GHz XBee-PRO offers a transmission range of up to 0.9 miles (1.4 km) in line-of-sight conditions and data transmission speeds of up to 250 kb/s.
The Windows-based Trooper in-vehicle mobile computing system features a fully sunlight readable (1500 nits) mobile data terminal and PowerShield 2.0, a multi-feature power management system that includes single-button shutdown and protects against battery discharge.
TRAKIT-Nationwide is a Web-based AVL tool designed for small to medium fleets. The company’s Web Mapping software simplifies the process of dispatching service vehicles and assigning employees to job tasks. A point-and-click database integrates vehicle location, customer addresses, job assignments, work completion status and other customer information. All pertinent information is displayed on screen in an easy-to-read format.
CrimeMapper plots crime information on a map to help law-enforcement agencies solve and prevent crimes and use resources more effectively. It lets users quickly evaluate patterns and densities of crimes or calls for service by location; crimes are plotted within date and time ranges, which lets agencies see where they need to enhance the presence of uniformed officers and investigators.
GenData uses a computer-aided dispatch-style interface to let first responders see the same active call information as the dispatcher. GenData also enables first responders to communicate back to dispatchers (including silent mode) and provides officers with real-time and historical incident information. The solution also provides text-to-voice, vehicle location and address information, full CAD mapping capabilities, and compatibility with third party GIS (geographic information systems), records management and field reporting applications.
The Centry II is a self-contained GPS receiver with a built in packet modem and transceiver that creates a stand-alone solution for AVL applications. It is equipped with an internal GSM/GPRS transceiver. The local GPS output can be used for real time, in-vehicle position display on a laptop using the company’s Street Light mapping software, which lets drivers know where they are at all times. Real-time position monitoring provides reports as soon as the driver speeds, stops the vehicle, begins moving again, or changes direction.
The NL900 and NL2400 stand-alone transceivers can be set up in minutes to virtually cut the cables between RS232/RS485/RS422 devices. They are powered by a 1000 mW 900 MHz or a 200 mW 2.4 GHz radio, and can be used for mobile and temporary settings as well as for fixed installations. Optional software enables custom configurations. In addition, the units use a proprietary communication protocol to provide secure local data transmissions. Because the protocol uses FHSS technology, the data remains reliable over distances of up to 20 miles line-of-sight (900 MHz).
The Navigo Map Console is an integrated map and vehicle display environment used in the company’s AVL/GPS vehicle and asset tracking systems. Logging, replay and reporting options let users analyze every aspect of their fleet’s operation. Other features include Phase 1 and Phase 2 E911, as well as Streetworks, the company’s proprietary public works management program. The console is compatible with a variety of map data formats.
Ortivus North America
GoTrack is a Java-based program that can be loaded onto select Java- and GPS-enabled cellular phones. Those phones can be assigned to vehicles in a first responder fleet to deliver the GPS-derived location of the vehicle back to the station via the company’s Sweet-CAD, AVeL-CAD or AVeL-BASE applications. Those applications display the GoTrack-assigned vehicles on a map, where they can be analyzed for better dispatch decisions.