Target uniformity in 11n antenna choice, Cisco says

12/01/08

Some time ago, a reader pinged me with a question about antenna use in 802.11n networks. A Cisco AP 1250 Draft N customer, the reader had been advised to use a single type of antenna consistently across his network. He wanted to know why, if there are three antennas at each end of a given 11n connection, he shouldn’t mix up the antennas he deploys to optimize performance.

Mobile device advice

11/24/08

Managing a new enterprise-wide mobile device deployment might create some unexpected challenges. I spoke recently with wireless VAR Dan Croft, head of Mission Critical Wireless in Lincolnshire, Ill., on this topic. Croft, like me, admits to being around back in the day of proprietary 4Kbps mobile data networks in the early to mid 90s. This wireless veteran offered up some basic tips and guidelines for making sure today's wireless handset deployments go smoothly.

Wi-Fi and DASs: A good mix or oil and water?

11/19/08

Enterprises frequently install equipment to boost indoor cellular service reception. While you will need a separate RF signal source for each licensed carrier's traffic you wish to amplify, the trend is for a single distributed antenna system (DAS) to support multiple broadband wireless signals - including Wi-Fi - in a single infrastructure. There are both pros and cons to adding Wi-Fi to your DAS.

When green initiatives and wireless are at odds

11/17/08

Every now and then, the luxury of a Greenfield deployment comes along. Starting from scratch provides the opportunity to create an eco-friendly environment and install the latest and greatest network technology. But what if the two goals are at odds?

Enterprises embrace Draft 11n

11/12/08

Until this year, enterprises have stood firm about waiting for final IEEE standards ratification before deploying the 802.11n wireless LANs. However, according to the recently published 2008 Webtorials Wireless LAN State-of-the-Market Report Series, they have grown far more willing to install "Draft N" products ahead of standards.

Wi-Fi, WiMAX or LTE: Which to choose?

11/10/08

I recently chatted online with representatives of the Wi-Fi Alliance, the WiMAX Forum and the GSM Association in an effort to understand how enterprises will apply emerging mobile broadband services going forward. With a quarter-million Wi-Fi hot spots worldwide, it's my take that Wi-Fi could become the default, pseudo "mobile WAN" of choice for the masses of traveling executives. Obviously, Wi-Fi won't cut it for field service workers or those out in the desert or on an oil rig. But for mainstream use, why choose a mobile data plan with its high data usage and roaming charges?

When a WLAN controller fails

11/05/08

In controller-based WLAN architectures, what happens if a controller fails, and what is its impact on availability of the RF access network?

WLAN availability: Beyond the air

11/03/08

The last few newsletters have examined industry efforts to improve over-the-air uptime in wireless LANs. But the RF portion of the network is just part of the equation. The AP infrastructure and WLAN controllers require high-availability schemes, too, to ensure that WLANs perform comparably to good ole Ethernet.

HA insurance for RF networks

10/29/08

The last newsletter discussed the high-availability challenge of wireless LANs and the latest move from Meru Networks to manage the RF environment to improve availability. Other vendors are on top of the issue in similar ways.

Mastering high availability in WLANs

10/27/08

For LANs to go "all wireless," they must achieve close technical parity with Ethernet. The wireless LAN industry appears hard at work to make it so.

Is 11n on a technical par with Ethernet?

10/22/08

The emerging high-speed version of Wi-Fi, 802.11n, is a driver toward the "all wireless" enterprise. This is an assertion made regularly by wishful-thinking vendors but one that has also been verified by recent research. Indeed, the speed is there. But are all the availability, security, reliability and QoS pieces also in place that would allow Wi-Fi to usurp tried-and-true Ethernet?

Lipstick on a COW (and a COLT)

10/20/08

First it was pit bulls and then it was pigs. Can we now add cows and colts to the list of metaphorical lipstick-wearing politicos this campaign season?

Med center surprises itself with WLAN choice

10/15/08

El Centro Regional Medical Center recently needed to overhaul and expand its outdated, fat-AP wireless LAN. A technical and economical bake-off helped the medical center - somewhat to its own surprise - decide on startup Aerohive for its 75-AP rollout, which began in April.

University reduces AP density - for voice

10/13/08

It's common wisdom that shops wishing to run voice over wireless LANs (VoWLAN) must deploy more access points than they would if installing Wi-Fi for data-only transmission. The denser deployments, of course, help plug coverage gaps that could otherwise cause live calls to disconnect. The University of Arizona, however, discovered that a too-dense AP deployment carries its own set of problems.

App acceleration for mobile users

10/08/08

An enterprise application on a mobile laptop not attached directly to the corporate LAN can perform abysmally without a bit of technical trickery. Companies such as Blue Coat, Cisco and Riverbed are prominent companies that boost application response times across the WAN, not only to users in branch offices but to mobile users, as well.

WiMAX, 3G, Wi-Fi battle for your business

10/06/08

The battle to woo you to a particular wireless camp has heated up in the past month. The first U.S. mobile WiMAX service went live last week, just as devices with embedded connections to worldwide High-Speed Packet Access (HSPA) 3G services began being aggressively marketed by the GSM Association. In the meantime, integrated, flat-rate global Wi-Fi voice and data service packages have also become available.

Smartphones are opening - but just a crack

10/01/08

There are several definitions of "open access." One is making open source code available to a community of smart cookies who can debug and modify it using open source mechanisms. Another is offering up low-cost or free software development kits (SDK) to encourage creative applications for a given platform. Another is offering middleware that allows an application developed once to run on multiple platforms. And, finally, in mobile networks, open can mean using a phone and its applications on any carrier's compatible network.

G1, other smartphones push 3G limits

09/29/08

We call 'em phones. But the new T-Mobile G1, the Apple iPhone and other touch-enabled handsets making the nightly news are really tiny multifunction computers optimized for music, video, photos or advertising. They also happen to make over-the-air phone calls. The applications being designed for them gobble up mass quantities of bandwidth, something that isn't all that plentiful in 3G networks.

Mobilization trends aided by latest middleware

09/24/08

There is significant application mobilization afoot within large enterprises for the remainder of this year. The plans may be fueled, in part, by sophisticated mobile software-as-a-service (SaaS) availability - offerings that increasingly bundle device management and security into the mix.

New vibe in sensor networks

09/22/08

What will reign as the wireless sensor network platform of the future? To date, the ZigBee Alliance has taken it upon itself to build networking and development standards for low-power, low-memory sensor devices communicating across 802.15.4 wireless personal-area networks. However, work toward promoting the use of the more pervasive and medium-agnostic IP protocol stack heated up last week with the formation of the IP for Smart Objects (IPSO) Alliance.

Online meetings to hit smartphones

09/17/08

A service allowing multimedia online meetings directly from mobile handsets will be announced at the Interop New York 2008 conference this week.

Software defined radios and 802.11n

09/15/08

Software-defined radios, or SDRs, persevere as a lively topic of discussion. An SDR enables a given radio to tune to variable frequencies to meet the specifications of different applications and country-by-country regulations. SDR capabilities are emerging as a consideration for 802.11n, which relies heavily on the 5GHz band for optimum throughput - a band that is subject to regulation around the world.

Tricks for cellular savings

09/10/08

When mobile users are traveling, cellular roaming costs can add up. The ideal solution would be for mobile operators all over the world to reduce their roaming rates, which, admittedly, is happening to a degree in Europe. In lieu of significant widespread reductions, though, the industry has begun chipping away at the problem with a variety of approaches.

Wireless voice calls gain encryption

09/08/08

Fixed-mobile convergence (FMC) start-up Agito Networks Monday plans to announce voice-over-Wi-Fi encryption and other features for its RoamAnywhere Mobility Router.

Latest 802.11 standards: Too little too late?

09/03/08

Both 802.11k for radio resource measurement/management and 802.11r for fast handoff among wireless LAN access points have recently been ratified. Their arrival reminds me a little of the discussions surrounding IPv6 a few years ago, in that many of the problems these standards were designed to address have, in the meantime, been solved in alternative ways.

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Joanie Wexler is an independent networking technology writer/editor in Silicon Valley.