| | Re: 802.11g vs 802.11n
Jeff Liebermann wrote:
> On Thu, 06 Dec 2007 15:48:04 -0500, jay lunis <firstname.lastname@example.org>
>> My interest in 'n' is, by far, more for the increased range.
>> Are you, and others, saying the range is not that much greater?
> I just happen to dribble by Office Max. On some 802.11n products
> being sold, the box declared:
> 4x the range. 12x the speed
> Sounds great? Well, they lie. (Everybody lies, but that's ok because
> nobody can understand the numbers anyway).
> First, you're NOT going to get both 4x the range and 12x the speed at
> the same time. If you believe the hype, it's one or the other.
> 2nd, 4 time the range of what? Compared to what device and under what
> conditions? I'm a bit busy right now (leaky office roof) so I'm going
> to suggest that you do the necessary Googling and see if any of the
> vendors that use this 4x and 12x manure bother to specify test
> conditions on their web piles. They probably do, but see if it
> actually resembles something you can use for comparison. Look for at
> what range they did the test, with what error rate, and using what
> client device for testing.
>> I need to reach wirelessly about 80-100 feet through 3 walls and one
>> floor. My 'g' can't reach that far.
> Neither can an 802.11n Draft 2 router go through 3 assorted walls of
> unspecified material and one floor of more of the same. If it's
> concrete, stucco, chicken wire, or aluminum foil backed insulation,
> you're lucky if it can go through one wall. The only way I know of
> going through 3 walls and a floor is with an electric drill and CAT5
> cable. If desperate, think about power line (HomePlug) or phone line
> (HomePNA) networking.
Well, my walls/floors are typical residential wood/drywall.
HomePlug has worked tolerably well but, since I tend to move around a
room, I'd rather not be tethered to a wire. Is there a way to send a
signal to a remote network device (wireless or wired) and have the
remote device send a wireless signal so I'm not forced to connect my
laptop to a wire/cable?
> Incidentally, my rule of thumb is where the 4x and 12x crap came from.
> The way Airgo style MIMO (spatial mux) works is to transmit multiple
> streams of data at the same time. So, if you're getting perhaps 100ft
> of reliable range at 25 Mbits/sec, then with Airgo style MIMO, you'll
> get two streams or twice the thruput. However, you can always trade
> speed for range. A 2nd stream will give you SQRT(2) times the range,
> if you drop the TOTAL speed of the two streams back down to the
> previous 25Mbits/sec. If you have 4 streams, and slow things down to
> 25Mbits/sec, you'll go 2x as far. To go 4x the range, you need 16
> streams, which I don't think any of the current incantations are able
> to deliver. Similarly, if you're expecting 12x times the speed,
> you'll need 12 streams, which is also stretching things a bit. Of
> course the spatial mux is far from perfect and tends to create some
> self interference. Your mileage may vary.