question on 802.11a, and 802.11g

[jjyiz28]

just some basic questions needing some answers

1) does 80211g operate in BOTH 2.4gz and 5gz or only 2.4ghz??
2) theoretically, 'g' and 'a' speeds are 54mbps. but in actual use, is 'a' faster since the 5ghz bandwidth is not currently used as much by consumer devices compared to the 2.4ghz bandwidth in 80211 'g'???
3) i read 802.11g is more backward compatible with 802.11b AP's, but how is this so?? i mean they share the same bandwidth range, but isn't there AP's that could support both 2.4ghz and 5ghz?? therefore with the right AP cant 80211a just be as compatible with 802.11b networks???

 

[Fencer128]

Originally posted by: jjyiz28
just some basic questions needing some answers

1) does 80211g operate in BOTH 2.4gz and 5gz or only 2.4ghz??

2.4GHz only. 802.11a uses 5GHz.

2) theoretically, 'g' and 'a' speeds are 54mbps. but in actual use, is 'a' faster since the 5ghz bandwidth is not currently used as much by consumer devices compared to the 2.4ghz bandwidth in 80211 'g'???

Not sure on this one. I guess it depends on a lot. I would think that unless you live in a very EM noisy or 802.11b/g cluttered environment, then channel interference won't be your main problem.

3) i read 802.11g is more backward compatible with 802.11b AP's, but how is this so?? i mean they share the same bandwidth range, but isn't there AP's that could support both 2.4ghz and 5ghz?? therefore with the right AP cant 80211a just be as compatible with 802.11b networks???

802.11b/g are 2.4GHz based, 802.11a is 5GHz based. You can buy dual band APs, etc. that support a/b or a/b/g but in themselves "a" is completeley incompatible with b and g. g is often only a firmware update away from compatibility with b as they utilise the same frequency characteristics/bandwidth.

Hope that helps,

Andy

 

[LordJezo]

Don't know if this applies but...

I tried a b network in my house and it stunk. Connections were always dropped and ping and lag in games was terrible.

Switched to a g network using PCI cards.. now you can't even tell it's wireless. To me g was worth the extra price for its reliability and speed.

 

[JackMDS]

On Wireless:

802.11b vs. 802.11g.

For Internet surfing it does mot matter since Internet broadband connection is slower than 802.11b

For traffic across Internal LAN, 802.11g is significantly faster.

General Wireless info.

802.11b = 11Mb/sec. Network "Speed" (Carrier transmission 2.4GHz)
802.11g = 54Mb/sec. Network "Speed" (Carrier transmission 2.4GHz)

Wireless Ethernet needs additional protocol over head for the transfer. In addition, it is not as stable as Wired so it needs extra processing procedures.

As a result the 11Mb/sec. of the Network chipset is translated to a much lower actual performance. Usually 4-6Mb/sec.

Few 802.11b hardware units are also capable to work at 22Mb/sec.(usually referred to as b+) it is nice if it works, in real term will yield 20%-40% more than 11Mb/sec. systems.

The 802.11g line that is rated 54Mb/sec. in the real world it yields 18-22Mb/sec.

The differences between the first set of graphs to the second represent the performance differences between 802.11b to 802.11g. It might give you a good idea about indoor's distance coverage. Your actual distance might be different. Indoor coverage depends heavily on the envioroment; graphs like this should be used to understand the relation in performance between Wireless hardware. .

Link: 802.11a/b/g SOHO Routers & Access Points: Performance

The following collection of links might help.

Ignore the prices in the links bellow. The same or similar hardware can be found for 60%-90% less.

Link: AnandTech - FAQ. What do I need for wireless Networking?

Link: Wireless Cable/DSL Router or Access Point - What should I get?

Link: Wireless Network - Configuration Modes.

Link: Wireless Security for the Home User.

Link: Wireless Network Troubleshooting,

Link: How do I use a Wireless Cable/DSL Router as a Switch with an Access Point?

What should I get.

Networking in General is no CPU OverClocking or "squeezing" few frames from a "puny" Video card, it is more complicated.

The number of variables that goes into the equation of each situation is so variant that it is impossible to give one rule of thumb.

If the Wireless Computer is going to be used in the vicinity of the Wireless Gateway, and you are going for 802.11b buy the cheapest you can find. You can get a Wireless Cable/DSL Router for about $29.99 + PCMCIA card for $19.99 (both after rebate).

To achieve the top of Entry Level Wireless performance (as of Sep; 2003) I would use a cheap Wired Router, and combine it with a 802.11g set of Access Point and Client Cards by either D-Link or Linksys.