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Mesh
installations offer ISP a way to improve their network operations. Approaching a
Mesh deployment in steps or phases can help make this process faster and more
efficient. The best way to add wireless connectivity is to start small and plan
with an eye toward expansion
 | Define
the scope, |
| Participants, |
| Zones, |
| Metrics,
and |
| Training. |
Popular
sites for wireless projects include homes, Multi dwelling, and Companies. It's
vital to obtain a good sampling from each location in which you plan to install
wireless Mesh. Plan for a realistic sample, depending on the pilot's scope, your
campus size, and user base to get results that are applicable to the larger
population. Include coverage for various home use, and business
— all of who will derive a different value from wireless.
Map
the wireless zones that participants will use, and determine the LAN wiring you
have in those areas. Uplink node hardware is hardwired to the LAN. Work closely
with your installers to incorporate wireless technology in ways that will
minimize rework as the Mesh expands. It may be useful to perform a site survey
in this stage.
At
the very start, lay out how you'll measure the production value index. Start
with a baseline measurement of costs before the pilot, and plan how to measure
and report productivity and return on investment (ROI) metrics afterward.
The
success of a pilot often pivots on how well participants and your customer
service are trained, and whether your support group can respond quickly to
requests for help. First impressions can make or break the success of the pilot.
Start early to document how users should get started, how to use the system, and
how to obtain support. Prepare trainers and FAQ’s for deployment, and train
your technical support teams thoroughly in the new technology.
Address
authentication and encryption concerns.
Configure
clients with the correct ESSID to access their Mesh. The key should be shared
only with those having legitimate need to access the network.
Filtering
addresses restricts Mesh access to computers that are on a list you create for
each access point on your Mesh Network. This should be enabled.
Encryption
scheme that protects Mesh data streams between clients and AP’s as specified
by the 802.11 standard. This should be turned on, but it should be realized that
flaws have been discovered in this mechanism.
MeshAP
has a bombproof security feature, ensure that you understand and implement it.
Perform
regular network audits to identify rogue access points and disable or
reconfigure them appropriately. Rogue access points are those installed without
your organizations knowledge and are generally not configured with any security
settings, which leaves an open door for unauthorized access.
This
technology offers additional security by creating a tunnel that shields your
data from the outside world. A common security policy for many corporations is
to require clients to use VPN to access the Mesh network through any wireless
access point; however, VPN should be installed on all clients OS to access the
Mesh. VPN do not work with other corporate VPN.
Select
and purchase equipment, and provide wireless adapters to participants.
After
determining, which Meshbox is right for you indoor, outdoor, environment,
antennas selections, etc. purchase
the appropriate number of access points for your pilot. Choose among the top
providers, especially those that will provide solid product support. Choose
access point units that offer interchangeable antenna options (for example,
omni-directional and directional antennas). These accommodate different spaces
so you can fine tune reception for optimal reach. Access point units need
electricity. Larger installations do best using power over existing
Ethernet/Cat-5 cabling to avoid expensive retrofitting of electrical wiring.
Make sure the units you buy Support Power over Ethernet or purchase products
that provide this.
Install
Wi-Fi network interface cards (NIC). Create auto-installers to install VPN
software, etc. in participants' PC or appliance.
Train
participants and gather data.
Set
up a training session and seminars for the Mesh clients. Make it easy and
mandatory for Mesh users to get training on their new systems — preferably at
the same time they receive their wireless-enabled PC. Set appropriate user
expectations for support and how they should request it. Then train participants
to actually call, report, and get help.
Gather
user feedback from the beginning of the pilot. This can be even more important
than technical feedback. Consider an informal system in which customer support
roam the wireless zones for immediate input from users. You might also schedule
interviews or drop-in lunch meetings to gather comments and reactions. Collect
intermediate metrics for ROI reporting and address technical issues as needed
during the pilot. Make sure to closely monitor the Mesh access and be prepared
to react quickly to seal security leaks or handle other problems.
Evaluate
the pilot and broaden WLAN reach.
Gather
and report findings and ROI values. Review ways you can improve systems to meet
needs that the pilot didn't address, such as additional access points, smoother
setup, or user support. Report the findings to stakeholders to get approval for
broader deployments. And communicate outcomes to all your pilot users because
they need to know what became of their efforts to help.
With
an eye to the larger organization, return to Step 1 and reassess the questions
and decisions you made for the pilot in light of scaling the Mesh to include
more zones. Decide whether to deploy wireless across the entire network, or
expand it selectively to serve the next level of mobile user needs. Standardize
security access across the site no matter how large the Mesh gets so users won't
run into lockout problems as they roam.
Locustworld
software supports a variety of network configurations, including 802.11b and
wired ethernet LANs in both ad-hoc and infrastructure modes. The following
guidelines address the specific features of each type that must be taken into
consideration when planning for installation of a Mesh Network.
An
overview of the differences between the two types of Mesh. It is important to
understand how each relates to the strengths and weaknesses, in order to
maximize overall system performance.
Expect
greater range from 802.11b, since technically the higher the frequency the
faster the signal will decrease with distance.
Expect
much greater throughput from ethernet. At any range, this could be 4-100 times
greater than that provided by 802.11b.
Other
legal signals in the same band make 802.11b more likely to have an interference
problem, which translates into poor data transmission.
To overcome this problem adding more mesh nodes and a better combination
of antenna and radio card is the answer.
Mesh
costs more to install, since more access points are required for a given area.
However, on a ”cost per transmitted bit” basis Mesh is considerably less
expensive than a traditional WiFi installation.
With
correct installation and implementation, Mesh offers good performance. If speed
and interference were not major considerations, 802.11b would be adequate. In a
small office in a building with many other types of microwave devices, cordless
2.4 phones, and generally noisy 2.4-gigahertz areas, ethernet would be a better
choice. On-site testing via the site survey process is the best way to get
accurate information on which type of network to use, or on how to create a
network in a both 802.11b and ethernet environment.
A
site survey done for an existing ethernet network installation will not work for
a Mesh network that replaces an existing wireless network or is added to a site
with an existing ethernet network. A new site survey should be done and a new
coverage area map and model should be created.
When
designing and setting up an 802.11b wireless Mesh in the same location, using
Mesh Box, keep the following considerations in mind:
| 802.11b
devices differ in range, coverage, and channel specifications |
| Dual
Access Points may provide greater coverage for 802.11b devices. Site surveys
involving Dual Access Points will need to consider the requirements for
both channels. In many cases it will be advisable to consider basing initial
Access Point positioning primarily on 802.11b requirements, and then adjust
settings as needed. |
| 802.11b
supports fewer non-overlapping channels. As a result, careful planning of
channel selection and positioning is critical, especially for Mesh
networks using site surveys based on wireless requirements. |
Consider
the degree to which the Mesh will interact with the conventional wired LAN. Some
legacy systems, such as older mainframe networks, may not support Mesh without
additional hardware or software.
The
size of the site determines what equipment you will need and where to place it.
These parameters will be different for Mesh network than for 802.11b networks.
See Mesh Topology for guidelines.
| A
small site requires fewer than 10 access points; two are usually sufficient. |
| A
medium site requires between 10 and 20 access points. |
| A
large site requires 20 to 100 access points and possibly some directional
antennas. |
The
shape of the site is also a concern. Radio frequency (RF) transmissions
propagate differently in indoor environment such as a narrow space, such as a
hallway, than in a large open area, such as an office filled with cubicles. Open
doorways might also affect RF propagation. Outdoor environments also have
different propagation. See
Environment effect for details.
The
right kind of power supply should be available for access points. The following
are electrical installation alternatives listed in order of most to least
desirable.
Dedicated
circuit with a Uninterrupted Power Supply (UPS) that also acts as a filter and
surge suppressor.
| Non-dedicated
circuit with a UPS. |
| Non-dedicated
circuit with a surge suppressor. |
Configurations
without a UPS are not recommended. A dedicated circuit is preferable to a
non-dedicated circuit. Non-dedicated circuits have open receptacles; the load
and type of use cannot be predicted at the time of installation. Although the
current draw of the access points is minimal, other devices on the circuit can
affect the access points.
If
it is absolutely necessary to have a non-dedicated circuit, it is recommended
that the circuit not support the following:
| Non-network
devices, such as lighting, powered directly from the circuit. |
| Devices
with components that produce heat such as space heaters, laser printers,
heat guns, soldering irons, or photocopiers. |
| Devices
that often cause sudden sharp surges in the power line contain medium or
large motors, such as electric staplers, refrigerators, and floor cleaning
equipment, air conditioners, fans, or any single device drawing more than 20
percent of the rated value the circuit. |
| Any
combination of devices drawing more than 60 percent of the rated value of
the circuit. |
In
all cases, the power to the access points must be unswitched and available 24
hours per day. It is recommended that the power never be provided from an energy
management system.
Physical
and environmental conditions affect the performance of Mesh Box. An Indoor
sites should not be excessively hot, cold, humid, or dusty. The area should also
be relatively free of electronic equipment that generates background Radio
Frequency (RF) noise, which can interfere with wireless LANs.
For
optimal performance, do not locate access points near transformers, heavy-duty
motors, fluorescent lights, microwave ovens, refrigerators, and other industrial
equipment. See the site survey section for environment recommendations.
Signal loss can occur when metal, concrete, walls, or floors block
transmission. Locate access points in open areas or add access points as needed
to improve performance.
For
simplicity, we talk of "moving around," but signals will also
travel up and down. This can be good or bad, depending on your situation.
The
good news is that, in a multistory building, you can usually
communicate between floors using one access point. As usual, the actual
range depends on the floor material, which can only be checked with a site
survey. Expect some dead spots directly over (or
under) large metal air conditioning ducts, and similar metal surfaces.
The bad news is that another wireless ISP or another wireless Access Point on
the floor above or below
you may innocently install its own system, and, for example, place an access
point directly below your desk. A bit of diplomatic mutual planning helps
both systems to operate at maximum efficiency. The
placement of access points, and the choice of channels, needs to be worked
out between users.
Some
elevators are transparent to microwaves, and others act as a
closed metal box. In the latter case, if network operation in the
elevator is required, you may have to install an access point in the
elevator. This requirement should be incorporated into your site
survey.
Some
of the equipment and materials that can interfere with wireless LAN
transmissions include:
| Equipment
that produces radio waves in the 2.4 or 5 GHz range |
| Existing
wireless LANs |
| Cordless
telephones or cordless telephone stations except for cellular telephones |
| Microwave
ovens closer than three meters (ten feet) from the antenna |
| Radio
frequency identification tags |
| Ceiling-mounted
sprinkler heads closer than 60 centimeters (two feet) to the antenna |
| Outdoor
broadcast television used by mobile television cameras |
| Uninterruptible
power supply (UPS) devices |
| Pine
trees with needles near wavelength or half wavelength |
| Large
heat-producing machines or chambers |
| Fluorescent
lights |
| Overhead
cranes |
| Overhead
conveyors |
| Elevator
shafts |
| Heavy-duty
motors |
| Lead
paint |
| Plants
and trees |
| Power
surge protectors |
| Refrigerators |
| Sulfur
plasma lighting |
| Transformers |
Obstruction
Degree of Attenuation
Open Space
None
Outdoors, Large indoors areas
Wood
Low
Inner wall, office partition, door, floor
Plaster
Low
Inner wall (old plaster lower than new plaster)
Synthetic
Materials
Low
Office partition
Cinder block
Low
Inner wall, outer wall
Asbestos
Low
Ceiling
Glass
Low
Non-tinted window
Wire Mesh in
Glass
Medium
Door, partition
Metal Tinted
Glass
Medium
Tinted window
Human Body
Medium
Large group of people
Water
Medium
Damp wood, aquarium, organic inventory
Bricks
Medium
Inner wall, outer wall, floor
Marble
Medium
Inner wall, outer wall, floor
Ceramic
High
Ceramic tile, ceiling, floor (Metal Content or Backing)
Paper
High
Roll or stack of paper stock
Concrete
High
Floor, outer wall, support pillar
Bulletproof
Glass
High
Security booth
Silvering
Very High
Mirror
Metal
Very High
Desk, office partition, reinforced concrete, elevator shaft, filing
cabinet, sprinkler system, and ventilator.
The
key to successful setup and installation of your Mesh is the site survey. The
main tools of the site survey are:
| A
Mesh Uplink Node, |
| A
laptop, set up as the "transmitter." |
It should
be mounted at the same height, and as close as possible to the same spot,
as you plan to use for your final installation
Use
a Laptop with a high gain antenna, to use as the mobile receiver. It must be
loaded with your site survey software such as Net Stumbler.
A copy of a building or area map, to plot your field strength data
If
you are installing a Mesh, verify that all of the above-mentioned
interfering systems, devices and gadgets are off, or if they must be on,
that they are indeed turned on. In the event of problems, try turning all
other systems off anyway, and repeat the tests. This will at least identify
your problem area.
The
survey procedure is simple: Move around your area and plot the strength of
your signal at various locations. Repeat the process for each intended
access point location. As you move around, you will probably encounter some
problems. Major area problems are usually associated with your
"transmitter" location. If you placed the transmitter on a wall
containing a metal air conditioning duct or similar metal surface, you will have
a serious problem with range, and a very large dead spot. Move the transmitting
unit and repeat the tests.
Localized
problems can be due to some hidden building characteristic. If you draw
connecting "equal strength" signal level lines on your map, it will
help you visualize problem areas, and may hint towards the best method of
addressing them. These tests will show you where to mount your access
points, and how many you will need to get good building coverage.
Seamless
coverage means that you can move around the entire coverage area, and always
stay connected. This requires software that can detect the fact that your signal
is dropping down at one access point, and going up at another, thus triggering a
seamless handoff between them. Keep in mind that this process will not work
unless there is a reasonable signal level overlap of the signals in the two
areas. If you lay out your system without this signal overlap, the user
will experience an annoying signal dropout as he moves around.
Done
with your building survey? Now go outside your facility, and repeat the
above measuring process. Check how far down the street your signal goes.
You can move your transmitter to increase or decrease this range as appropriate.
Here you need to take a ladder and move on rooftops, poles etc to measure signal
strengths.
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