troika4
join:2003-07-30
New Haven, CT
| Wireless PCMCIA Cards: Milliwatt Output
Hello Group,
You've been extremely knowledgeable, helpful, and patient in the past, and wish to absorb your collective intelligence yet again.
First, a question: Is it true that milliwatt output is a crucial factor in the signal consistency and range of an 802.11b/g wireless pcmcia card on a notebook computer?
If the answer is yes, then I really need help in finding the milliwatt output ratings of such network cards. On most spec. sheets all I see are references to "Antennae Gain - 1.5 DBM". Is this referring to milliwatt output? I don't know. Basically, I want to find the highest milliwatt output cards and shop for them; is there a good place on the net that provides complete information on the matter?
Thank you for your help.
Troika |
|
dbmaven
There's no shortage
Premium,Mod
join:1999-10-26
Sty in Sky
clubs: | This will do better in the Wireless Networking forum...
--
"Q: When will it be done? A: When pigs fly! " |
|
troika4
join:2003-07-30
New Haven, CT | reply to troika4
Thanks dbmaven. |
|
decx
Premium
join:2002-06-07
Vancouver, BC
 ·Bell Sympatico
| reply to troika4
How well a wireless NIC hold onto a signal depends mainly on three things, the radio output, radio sensitivity, and antennae gain. They're all different things.
Simply, more output power only helps the signal sent by the NIC to reach the AP and has nothing to do with how well it picks up the incoming AP's signal.
Radio sensitivity is the opposite and the better this is, the better the card is able to hold onto a weak signal.
The NIC's antennae gain, helps with both, by acting like a RF lens to focus it's output signal and collecting incoming signals. The higher the gain, the more focused the radiation "pattern" will be, however, this sacrifices certain areas at which the antennae is not focusing on.
Btw the crowd at the Wireless Networking forum will probably be able to handle your question with a better and more detail answer. |
|
troika4
join:2003-07-30
New Haven, CT | reply to troika4
hmmm, looks like a 1.5 dBm antennae output may be equivalent to 1.5 milliwatt output. This seems extremely low. I want PCMCIA cards that have outputs of 200 milliwatts or more.
Troika |
|
No_Strings
Premium,Mod
join:2001-11-22
The OC
Host:
Wireless Networking
All Things Unix
Cox HSI
Qwest
Efficient
| Some comparisons here: »www.seattlewireless.net/index.cg···mparison
Wireless cards with 200mw or more transmit power and (important word) decent receive sensitivity include: Demarctech, Senao/Engenius, Zcomax (AKA SMC 2532B-w) |
|
troika4
join:2003-07-30
New Haven, CT | Hi NoStrings,
Thanks for the pointer to some decent products to check out.
I will do so and see if their literature plainly states the milliwatt output and "receive sensitivity" stuff.
Thanks for your time.
Troika |
|
troika4
join:2003-07-30
New Haven, CT
| reply to No_Strings
NoStrings,
This Demarctech [DT-RWZ-300mW-WC] pcmcia network adapter looks awesome.
I'll follow up with one more question: Do you know of any more powerful wireless adapter than this one. 300mW is the highest card of this type I've found on the net.
My buddy is willing to spend the $$, he just wants to know that he's done everything he can do to maximize his range and signal power.
Thanks for your help.
Troika |
|
No_Strings
Premium,Mod
join:2001-11-22
The OC | I've not seen one more powerful. Demarc actually suggests that the 300mw cards only be used for embedded applications such as a wireless access point. It's probably pretty hard on laptop batteries. |
|
troika4
join:2003-07-30
New Haven, CT
| Heh!
That sounds perfectamundo. 
My buddy will want it all the more, after hearing it's so powerful that it will mercilessly drain his batteries.
Niiice.
Thanks for the feedback, I really appreciate the help.
Have a great weekend.
Troika |
|
vincentfox
join:2003-03-18
Davis, CA
2 edits | reply to troika4
I don't understand the fascination with transmit power. This is 2-way, and you are usually subject to interference issues in urban environments that are of overriding concern.
I much prefer the HawkingTech HWC54D card. Has a 6 dBi panel antenna that pops up and you can focus your gain on both transmit and receive in the direction you want. It is important to hear well too, you see? By focusing your receive sensitivity a particular direction, you improve that as well.
Willing to bet it would hold a signal further out than those other cards. |
|
troika4
join:2003-07-30
New Haven, CT
| Vincent,
Thanks for your response.
I guess I still have alot to learn about these cards.
I thought the transmit power would also imply that it can pull in signal to the same degree of power as well. The sensitivity ratings looked good so I thought it would "listen" as well as it broadcasts.
I actually showed my friend something similar to what you're talking about with the antenna-thingy but he didn't like that. He wants just a stream-lined pcmcia adapter card.
Troika |
|
vincentfox
join:2003-03-18
Davis, CA
4 edits | reply to troika4
Let me use my usual analogy:
Tom and Dick on opposing hills trying to yell messages to each other. They are too far apart.
So Tom goes and buys a $100 "bullhorn" so he can yell louder. Now Dick can hear Tom, but Tom still cannot hear Dick. They are not communicating. For internet needs you must be able to hold a 2-way conversation, at minimum Dick wants to let Tom know to sing a song for him. So should Dick also buy a $100 bullhorn?
The smart thing for them to both do would be fashion a large cone called a megaphone. This lets you directionalize your shout and amplify it. You can also hold it up to your ear and hear better. For a few cents worth of cardboard they can get their job done.
Get it now? Good antenna are usually a better and cheaper solution than increased power. Higher power and a crappy antenna just wastefully broadcast more power in MANY directions, creating interference problems with the neighbors that cause them to escalate, or call the police. |
|
troika4
join:2003-07-30
New Haven, CT
| Vincent,
Think I'm catching on (and I don't mind if you dumb it down to kindergarten level, either.....totally appreciative of help with all these concepts).
So I've been seeing some pcmcia cards that have ports on them to attach external antennas. I think this is what you are talking about. Correct?
Troika |
|
No_Strings
Premium,Mod
join:2001-11-22
The OC | Yep. Most of the cards I referenced either have external connectors or come in an external antenna-only version. |
|
vincentfox
join:2003-03-18
Davis, CA
1 edit | reply to troika4
My usual traveling right now is a simple Orinoco Gold card. This has a single external connector. I have a 5 dBi blade antenna I velcro to the back of my laptop for general usage. The blade antenna gets me pretty good reception and being an omni it doesn't require much aiming. As a flat black blade you hardly know it's there. I have a couple of velcro pads in different places so I can reattach it sticking up higher from the top edge for example.
For more reach, I have a "pigtail", a short adapter wire that goes from the Orinoco plug and that ends in the industry-standard N-Male connector. I use this to hook up assorted directional antenna. Usually this is a 12 dBi cantenna on a small tripod. |
|
