If you’ve been a little confused about all the different WiFi standards, here’s a link that will sort it all out. The major standards you need to know about are as follows along with their salient features:
| Protocol |
Release
Date |
Op.
Frequency |
Throughput
(Typ) |
Data
Rate (Max) |
Modulation
Technique |
Range
(Radius Indoor) Depends, # and type of walls |
Range
(Radius Outdoor) Loss includes one wall |
| Legacy |
1997 |
2.4
GHz |
0.9
Mbit/s |
2
Mbit/s |
|
~20
Meters |
~100
Meters |
| 802.11a |
1999 |
5
GHz |
23
Mbit/s |
54
Mbit/s |
OFDM |
~35
Meters |
~120
Meters |
| 802.11b |
1999 |
2.4
GHz |
4.3
Mbit/s |
11
Mbit/s |
DSSS |
~38
Meters |
~140
Meters |
| 802.11g |
2003 |
2.4
GHz |
19
Mbit/s |
54
Mbit/s |
OFDM |
~38
Meters |
~140
Meters |
| 802.11n |
June
2009[4]
(est.) |
2.4
GHz 5 GHz |
74
Mbit/s |
248
Mbit/s |
|
~70
Meters |
~250
Meters |
| 802.11y |
June
2008[4]
(est.) |
3.7
GHz |
23
Mbit/s |
54
Mbit/s |
|
~50
Meters |
~5000
Meters |
Source: http://en.wikipedia.org/wiki/IEEE_802.11
If you want to learn more about the different standards, visit Wikipedia here. 802.11n is the way to go right now, if you can find a cost effective access point. Normally you’ll see mostly 802.11b/g access points.
Wateen Telecom has officially launched its WiMAX / HFC services in Pakistan and it is a major breakthrough in Pakistan’s broadband market. It is a joint venture of Wateen Telecom and Motorola, where Motorola played a major role in the deployment of first commercial 802.16 (d/e) network. Right now WiMAX service is available in 20 cities, which includes R.Y.Khan. It will provide cost effective alternative to existing broandband users. WiMAX is capable of supporting Triple Play (Internet, Voice and MultiMedia services) using single CPE (Consumer permises Equipment). For details visit their website
VoFi stands for Voice over Wi-Fi. Whenever you use your VoIP connection over a wireless connection, you are using VoFI. Do you have people connecting to the network via Wi-Fi connection and then using a soft phone to make a call? Then you are using VoFi.
For a few people, a regular data Wi-Fi connection works fine, but when you are planning on rolling out VoFI for a large number of people, a shared data Wi-Fi connection will not work.
To successfully use a Wi-Fi connection you need to make sure your corporate wireless connection has high bandwidth to host voice connections, low lag times and fewer hops. You may need a higher number of access points if you plan on using voice over the connection compared to plain data.
You can get away with using VLANs on same access points, some companies go a step further and setup a totally separate network for voice. Normally if a company is using 802.11b/g for data, they might want to consider using 802.11a for voice since they use different frequencies and this minimizes any chance of interference.
The best thing you can do is to perform an extensive and comprehensive wireless survey before rolling out VoFI. Take care of all the problem zones and if at all possible have a separate Wi-Fi infrastructure for voice side. Using a 802.11a connection would be better for voice and/or video since this standard offers more bandwidth and is less interference prone compared to the 802.11b/g standard.
