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Lehman Bros. adds Wi-Fi to signal distribution system

Jul 19, 20043 mins
Cellular NetworksNetwork SecurityWi-Fi

* Investment bank uses in-building signal amplifier

Increasingly, enterprises seem to want better cellular coverage inside their buildings, where various types of interference might keep signals from propagating well.

Such was the case at Lehman Brothers in New York. The global investment bank installed a wireless cabling plant from MobileAccess Networks, to augment and better distribute its cellular coverage for workers who use their cell phones frequently and for users of BlackBerry PDA-style voice/data devices. 

The need arose when some departments within Lehman Brothers took up residence in a new building in metropolitan New Jersey. The construction – particularly the reflective glass used – tends to distort signals, explains Ed Coffey, vice president of mobile engineering.

Once the MobileAccess system was in place, the company decided it could also use the platform to condition and distribute its Cisco-based wireless LAN (Wi-Fi) signals, Coffey says. The main goal with the MA-850 Wi-Fi module – commercial availability is being announced this week – is to save on operational costs and for security, Coffey explains.

In the MobileAccess architecture, physical access points (AP) reside in a locked telecom closet. Only antennas (made by MobileAccess) are distributed around the building, Coffey explains. “This means APs are in a secure place. Also, you can tune the power levels of each antenna to the edge of a window so they’re not blasting signals outside.”

Operationally, he says that every time he wants to add APs, he won’t have to drag them around the building to install them; rather, they get installed in the wiring closet.

An “RF switch” from MobileAccess allows any AP to communicate with any Wi-Fi antenna. This allows for an N+1 redundancy configuration in the wiring closet rather than installing extra numbers of APs in ceilings in case one should fail, says Jeff Kunst, MobileAccess vice president of marketing.

N+1 redundancy is a proven method of cost-effectively building in back-up hardware components to protect against downtime associated with outages in wired switching environments. In this case, instead of requiring a 1-to-1 backup of each AP, which can become quite expensive, just one extra AP per “n” number of APs can simply be installed in the wiring closet. Should an AP fail, the extra AP can automatically kick into action.  The MobileAccess RF switch will associate that back-up AP with whichever antenna in the building requires it.

The MobileAccess infrastructure propagates a variety of wireless signals throughout a building using a combination of coax and fiber. Wireless signals are picked up and delivered very near the wireless parties via MobileAccess antennas.

A mobile base station in the basement of a building feeds to modular remote cabinets (MRC) in wiring closets, which can be outfitted with a variety of wireless module types, such as cellular, paging, two-way radio, and now Wi-Fi APs from nearly any third-party vendor.

The MA-850 Wi-Fi module supports four APs; the ink was drying on a purchase order for nine of them last week at Lehman Brothers, which had already installed six MRCs for its cellular requirements, according to Coffey.

“The real driver was cellular,” he emphasizes.  “The new construction was killing BlackBerry coverage. Once the platform was in place, we found we could add [Wi-Fi] to it incrementally for very little money.”