Archived from groups: comp.dcom.lans.ethernet (
More info?)
"Walter Roberson" <roberson@ibd.nrc-cnrc.gc.ca> wrote in message
news:cpoie5$gq3$1@canopus.cc.umanitoba.ca...
> In article <1103077741.951461.106160@c13g2000cwb.googlegroups.com>,
> <santa19992000@yahoo.com> wrote:
> :Also I can see "Data Rate/Channels: 1-54MBps / 14 channels)". What is
> :the Channels meaning here?. is it Maximum of 14 laptops can be
> :connected simultaneously?.
>
> No, there are 14 frequency bands allocated, with different subsets
> of those being legal to use in different parts of the world. My
> probably incorrect recollection is that channel 14 is
> only authorized in France (which doesn't allow some of the
> lower-numbered bands.)
>
> When the radio is transmitting on a particular "channel", then
> the peak energy is going to frequencies near the official channel.
> However, with 802.11b there is also significant energy transmitted
> in the two frequency ranges on other side of the centre. This causes
> some degree of interference with transmissions on those other channels --
> for example, if there is a nearby device transmitting on channel 8
> then the energy it transmits in the range allocated to the centre
> of channel 6 might turn out to overwhelm the energy from a more
> distant device which is transmitting its peak energy in channel 6.
>
> Because of this overlap and potential for interference, you will
> often hear the guideline that that if you have multiple devices
> in an area, you should set them to be 5 channels apart, such as
> using channels 1, 6, and 11. That should be understood as a guideline
> and not a hard rule, though: it depends on your antennae and the
> signal strength from the overlapping chanels -- and there is a lot
> of redundancy in the transmitted data. Someone did an analysis of
> the energy patterns and determined that in all but the worst cases
> (device very close to each other), you could safely use channels
> that are only 3 apart, thus getting 4 effectively non-overlapping
> channels in the range of 11 that are permitted in USA/Canada.
>
> 802.11g works on similar principles, but is defined in such a way
> as to effectively "hard-code" the 1/6/11 guideline -- you only
> have a choice of 3 channels for 802.11g.
>
> 802.11a does NOT work on the same principles, and all of its channels
> can be used without interference.
>
>
> :I have Netgear WLAN Router (connected to Broadband through DSL), how
> :can I know howmany laptops can be connected simultaneously to the
> :Router?. How I will know?.
>
> It depends on -which- Netgear device you have. The reference to 54
> megabits per second and to channel 14 lead me to suspect you have one
> of the 802.11g routers such as Netgear's WGR614. It is often quite
> difficult to find information about how many devices an AP/router
> supports. What you are looking for is the "size of the MAC table" or
> "number of entries in the ARP table".
>
> I happen to have researched this figure a couple of weeks ago for the
> Linksys WAP54G. Linksys apparently told someone the limit was 5000. One
> highly respected wireless expert over in alt.internet.wireless (the
> place I suggest you post nearly all your wireless questions to) tested
> the Linksys WAP54G and found it can handle 253 clients.
>
> I'm going to hazard a guess that your Netgear might be the
> WGR614v4. If so, then if you look in the reference manual in the
> Key Features of the Router section, you will find:
>
> Parents and network administrators can establish restricted access
> policies based on time-of-day, web site addresses and address
> keywords, and share high-speed cable/DSL Internet access for up to
> 253 personal computers.
just be aware that there is likely to be a much lower limit on the number of
simultaneous wireless devices (as opposed to devices connected via ethernet)
alt.internet.wireless is a good place to ask, but i would be surprised if
the Netgear can handle more than 15 or so wireless devices.
>
> 253 is the same number given in the v1 and v5 reference manual;
> I'm not going to bother looking at the v2 and v3 reference manual
> for completeness ;-)
> --
> IMT made the sky
> Fall.
--
Regards
Stephen Hope - return address needs fewer xxs