Posted by Philip Wegner on Thu, Apr 15, 2010 @ 03:40 PM
Traditionally 802.11 wireless site surveys can cost upwards of $2.5K to $10K depending upon the size of your facility and applications you’ll need to work on the wireless LAN. It costs even more to buy the expensive wireless LAN site survey test equipment and train your own staff to do it. So the question often comes up:
With all of the free wireless site survey software tools out there, is it necessary to spend a lot of cash on 802.11n planning?
Answer: It depends on what you’re planning for. Let me explain in more detail.We design, deploy, and support many large scale wireless LANs across the country. We like to think of large scale wireless deployment as any wireless LAN infrastructure that will include more than 100 wireless access points. For simplicity, we break the wireless planning down into two categories:
1) Simple Planning: Coverage and Capacity (only): The users in this environment will primarily need wireless internet accessed through laptops, tablets or other mobile devices such as smart phones. An example is Wireless Networking for Schools like the 1:1 Initiatives and E-Rate funding for Internal Connections. For these wireless LAN deployments, predictive survey tools can be used (i.e. AirMagnet, AirWave, Ekahau) and can provide accurate analysis of what the coverage will look like. We still certainly recommend working with a wireless design expert in these tools to look at capacity concerns (see Capacity vs. Coverage Article). However, it is not necessary to set up the tripod, survey kit, walk the entire facility, and map out every access point location physically. Predictive tools are an inexpensive and great option for wireless LAN planning in K-12 and higher education environments.
Helpful Tip: When pulling network cabling to the access point location, leave a service loop of 10-15 ft to allow flexibility for adjustment of the access points for optimal coverage. In our experience, the predictive software tools are accurate within 5-10% of the real world RF coverage.
2) Complex Planning: Coverage, Capacity, AND Performance: The users in this environment will connect via traditional means but also have the need for applications that have very specific performance requirements. An example of this is a hospital wireless network that needs to support Wireless VoIP, Real Time Location Services (RTLS), Wireless Video, and Mobile Electronic Medical Records (EMR). Some applications, like RTLS for example, are only accurate based upon the location and spacing of the access points because it works off of triangulation of the signal (similar to GPS). In a hospital wireless networking environment, a site survey and testing on site is necessary to ensure the investment in wireless LAN infrastructure will be well founded.
Helpful Tip: When engaging a resource for wireless design, (1) define the applications/devices that will need to work in the facility, (2) define where they will need to work, and (3) define how accurate (for example: RTLS within 20 Ft.). The wireless designer can then determine the technical requirements of each application/device and use the proper tools to give you the best results.
About Secure Edge Networks, LLC
Secure Edge Networks, LLC, a specialty IT Solutions Provider focused on areas of Mobility, Security and Network Convergence for Schools and Hospitals in the South East. To learn more, visit www.securedgenetworks.com
# # #
Philip Wegner
Secure Edge Networks, LLC
+1-704-688-9355
pwegner@securedgenetworks.com
© 2010 Secure Edge Networks, LLC. All rights reserved. Offers are subject to change without notice.
Posted by Philip Wegner on Mon, Apr 12, 2010 @ 02:02 PM
With the E-Rate Service Substitution policy, K-12 Schools can use existing funding for wired networking to fund 802.11 Wireless Network Deployments.
We've been contacted by many K-12 institutions that have experienced exponential growth in 802.11 wireless networking usage since they filed their original technology plan and subsequent 470/471. The question is whether they can transition some of the funds USAC has committed for fixed Ethernet infrastructure (Internal Connections) to fund 802.11n wireless infrastructure. USAC has added specific language to the Service Substitution guidelines that addresses this exact request. Specifically, here is what's mentioned:
"Service substitutions may also be obtained in certain cases even when the Function categories are not identical. For example, an Access Point is a wireless networking component that is categorized in the Eligible Services List under the Data Distribution function. Networking cable is categorized under the Cabling function. Yet, since both network cabling and wireless access points can accomplish the same function of connecting network components, a service substitution to convert from one technology to the other can be approved."
The process is simply to follow the service substitution guidelines, but specify that the request is to convert between Function categories that are intended to serve the same primary function – connecting network components. This will allow funds that are currently allocated for wiring and Ethernet infrastructure (under internal connections) to be converted to funding for Wireless LAN infrastructure.
More detail on service substitutions and examples of substitution requests can be found here: http://www.universalservice.org/sl/about/changes-corrections/service-substitutions/
SecurEdge Networks E-Rate program offering a free Wireless LAN Site Survey: http://www.securedgenetworks.com/e-rate-offer/
About Secure Edge Networks, LLC
Secure Edge Networks, LLC, a specialty IT Solutions Provider focused on areas of Mobility, Security and Network Convergence for Schools and Hospitals in the South East. To learn more, visit www.securedgenetworks.com
# # #
Philip Wegner
Secure Edge Networks, LLC
+1-704-688-9355
pwegner@securedgenetworks.com © 2010 Secure Edge Networks, LLC. All rights reserved. Offers are subject to change without notice.
Posted by Philip Wegner on Wed, Mar 17, 2010 @ 03:30 PM
How much space can one wireless access point cover?
Before performing a wireless LAN site survey, this is an important question to understand. However, the most overlooked and a forgotten component of a wireless site survey is the coverage versus capacity challenge.
802.11 Wireless Coverage
An enterprise grade wireless LAN access point can cover 5,000 to 10,000 square feet of space. The variables to coverage are the power settings, antenna gain, and the physical environment. The newer systems built for the healthcare and education markets will auto adjust power and gain for optimal coverage. But wireless planning isn’t as simple as drawing circles on a floor plan.
So what if my medical clinic or campus building is only 20,000 square feet? Does this mean that all I need to cover my facility is two access points?
802.11 Wireless Capacity
The answer of how many access points to deploy depends on how many wireless clients will be accessing the wireless LAN simultaneously (system capacity) and in which places in the building (access point capacity). Wireless clients are defined as any wireless device that would be attaching to the WLAN and accessing resources from the network.
Look at your facility layout, and consider which areas will be hotspots for wireless users. For example, wireless in hospitals will have nursing stations where users will congregate and be carrying wireless VoIP phones, badges, and tablet PC’s. School campuses where there are large classrooms, auditoriums, and lecture halls. These environments have in common the potential to contain a large numbers of WLAN clients. Now you'll need to determine which access points have the potential to be over utilized.
From our experience, consider this for optimal capacity planning:
Client Type # of Clients/AP Examples
Data 20-30 Laptops, tablet PC’s, Mobile Carts, RFID Tags, Hand Held Scanners
Voice 10-15 Wireless VoIP Phones, Nurse Badges
Combine this formula with a wireless LAN solution with the system capacity to handle the number of clients in your plan and you’ve got a good starting point for a successful wireless network deployment.
