Which wireless network type do u use??
Which wireless network do you use at home/office?
Vote for the one you use or the one you think is the best!
802.11A
The 802.11a standard has three key advantages:
* Speed
* Installation flexibility
* Interference-handling advantages
If speed is a high priority in your network plan, you may want to look to proprietary 802.11a products. Several vendors are supporting doubled data rates of 802.11a devices, providing maximum link rates of 108 Mbps. This may be termed 802.11a Turbo Mode (Atheros chip sets) or 802.11a 2X Mode (Proxim). Be sure to examine these solutions closely to ensure multivendor support. Products may be Wi-Fi certified for standard operation, but uncertified for proprietary speedups.
The SAM also supports SD memory cards, so you can leave your PC at the office and present directly from the projector. Simply transfer your presentation to a memory card, insert the memory card in the projector, and present.
802.11a provides maximum flexibility if you need to use 20 or more access points and have them scattered on adjacent floors of a building. All vendors seem to support at least eight channels, and others will go as high as 13 in the United States and more in other countries, making it easier to configure overlapping access points. Bottom line: even eight channels for 802.11a are much more flexible than the three available with 802.11b/g.
Although 802.11a is by no means immune to interference, it's likely to encounter less interference simply because of the 5 GHz frequencies on which it broadcasts. The reason? The 5 GHz band is shared by far fewer devices than the 2.4 GHz band used by 802.11b/g.
The most common criticism of 802.11a is its limited reach. If there are distant users on the network that are operating at a low data rate due to a weak signal, they can degrade performance for other users of the same access point. The cost savings of installing wireless versus wired networks can be eaten up by the necessity of adding additional access points to maintain throughput.
There's one additional drawback to 802.11a: Regulatory requirements don't allow for an external antenna for use on some of the broadcast channels. As a result, use of an external antenna to solve implementation problems is not available. Some access points allow some adjustment of the signal, so there's the potential to solve some problems with additional access points. Regulations also prohibit use of some 802.11a channels outdoors.
In summary, 802.11a offers:
* High speed with proprietary solutions over 100 Mbps.
* Configuration flexibility with more than twice as many transmission channels compared to 802.11b/g.
* No appreciable interference from common electronics devices.
* Most limited coverage area of the three 802.11 implementations.
* Restrictions on external antennas and usage outdoors.
802.11B
The 802.11b standard provides high-speed access at up to 300 feet from the base station and it is the standard supported by most wireless hot spots around the country, including hotels and conference centers. If universal access is important, you probably want to support this standard. Also, because it has been around the longest, there's more expertise and experience available in personnel, case studies, and documentation to rely on. 802.11b devices have matured, and "rev 1.0" bugs and implementation questions have been resolved. Many wireless devices still support only 802.1b.
One of the major limitations of this standard is the very limited availability of data channels. To avoid interference between access points and to allow users to roam between them, access points communicate on their own non-overlapping channel. Wireless adapters synch to the access point with the strongest signal and don't suffer from the interference caused by a weaker signal of a separate access point that also reaches that area. For this to work, the signals can't overlap. Because there are only three available channels for 802.11b (and 802.11g), technicians need to be very careful in the placement of the access points so that no two access points broadcasting on the same channel have overlapping coverage areas. This poses special considerations when wireless networks are operating on adjoining floors because the signal moves vertically as well as horizontally. You don't want interference from the wireless network of the company upstairs or downstairs.
The other potential drawback of 802.11b (and 802.11g) is the spectrum it uses to broadcast. A few years ago, people started moving from 900 MHz cordless phones to 2.4 GHz phones for better sound and operation over greater distances. There were some reports of interference from microwave ovens and other devices, so many phone models added features to allow the user to change the communication channel. Now 802.11b and 802.11g networks are being added to the area already used by phones and microwaves. If you cannot eliminate the source of interference to a network access point or client, you may have to change the channel it broadcasts on. If there are other overlapping access points, they must be configured not to conflict with the changes. A small business with few access points will likely have no problems, but a large company with many access points on multiple floors will have to do some careful planning.
In summary, 802.11b offers:
* Good coverage, especially compared to 802.11a
* Mature with stable products and widespread availability
* Slowest of the three standards
* May be difficult to scale due to only three overlapping channels available
* Many other devices may insert interference in the 2.4 GHz broadcast range
Tip: If universal access is more of an issue than scalability, 802.11b might be the solution for you. If you already have an installed base of 802.11b users and want to migrate to a faster infrastructure, you should consider 802.11g.
802.11G
802.11g provides the coverage of 802.11b and the speed of 802.11a. It can be integrated into an 802.11a environment without interfering with the existing network and because its broadcast frequency is the same as 802.11b, it is backward-compatible and provides a smooth migration to better performance. Because 802.11b and 802.11g broadcast in the same 2.4 GHz frequencies, 802.11g is just as susceptible to interference as 802.11b, but in this shared drawback, 802.11g does have a few advantages.
The major advantage over 802.11b is speed. Although the specification for 802.11g requires support for speeds of only 6, 9, 12, 18, and 24 Mbps, you'll find that all Wi-Fi certified devices support speeds up to 58 Mbps. If your wireless clients are running bandwidth-intensive applications, you should move from 802.11b to 802.11g.
Another advantage of 802.11g is the general availability of improved security out of the box. Legacy 802.11b and 802.11a devices supported only standard WEP security and need to be upgraded. When 802.11g arrived, the security issues were already well known; therefore, enhanced security will be present in Wi-Fi certified devices, and upgrade capability is generally included for future improvements.
802.11g also has advantages over 802.11a. Although the two standards support similar data rates, 802.11g supports higher rates over a larger area. There are a few 802.11a supporters and manufacturers that dispute this fact or its importance, but it's generally accepted that for most devices currently on the market, 802.11g operates faster at greater distances and provides access to more distant clients. Also, 802.11g devices can use external antennas but, due to regulations, 802.11a devices can't. With all the advantages mentioned so far, you'd think that 802.11g would dominate. But one should consider the disadvantages specific to 802.11g.
Two of 802.11g's strengths are potential weaknesses for certain implementations. The backward-compatibility with the 802.11b standard can potentially reduce the speed benefits of the standard. When an 802.11b client attaches to an access point that supports 802.11g, all the 802.11g clients on that access point are negatively impacted. To ensure proper operation of the network, the collision-avoidance protocol requires that high-speed 802.11g utilize RTS -- STS (Request To Send -- Clear To Send) packet exchanges that the 802.11b stations can recognize. Maximum data throughput may drop below 20 Mbps. This may not be noticeable for applications that don't relay heavily on network access, but power users with network-intensive requirements might see an immediate delay in application response. It seems you can have speed or compatibility, but not both at the same time
In summary, 802.11g offers:
* High speed for network-intensive applications.
* Support for 802.11b clients.
* Coverage equal to 802.11b (greater than 802.11a).
* Improved security out of the box.
* Susceptibility to interference in the 2.4 GHz bandwidth.
* Backward-compatibility that comes with a performance cost.
802.11N
IEEE 802.11n is a proposed amendment to the IEEE 802.11-2007 wireless networking standard to significantly improve network throughput over previous standards, such as 802.11b and 802.11g, with a significant increase in the maximum raw (PHY) data rate from 54 Mbit/s to a maximum of 600 Mbit/s. The current state of the art supports a PHY rate of 300 Mbit/s, with the use of 2 spatial streams at a channel width of 40 MHz. Depending on the environment, this may translate into a user throughput (TCP/IP) of 100 Mbit/s. 802.11n is expected to be finalized in November 2009, although many "Draft N" products are already available.
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