dezt Posted January 18, 2007 Posted January 18, 2007 We have an astroturf playing field which the PE dept. use a lot of the time, the only problem is they have problems doing their registers, and have to try and remember who was there. They have all been bought HP IPAQ's with built in wireless 802.11b, and they all have pocketpars installed on them. I was wondering if it was possible to create a wireless link from our main building to the astroturf. The distance is between 1/2 a mile and 1 mile. There are no obstructions between the school and the astroturf. What would I need equipment wise if it is possible?
plexer Posted January 18, 2007 Posted January 18, 2007 An external or internal access point with an omni directional aerial on it? Is there power available at the astroturf location? Ben
tosca925 Posted January 18, 2007 Posted January 18, 2007 I was thinking POE (Power over Ethernet) but i bet the run is too far.
Ric_ Posted January 18, 2007 Posted January 18, 2007 Could the register not be taken before going to the field? 1/2 a mile is pretty far when talking about 802.11b... you would need to get an antenna within 100m of the astroturf and this could prove costly.
plexer Posted January 19, 2007 Posted January 19, 2007 You have a duct all the way to the field with no power running in it to be able to put in cat5e? Ben
webman Posted January 19, 2007 Posted January 19, 2007 A directional antenna pointing towards the astroturf would concentrate the signal in that direction so it might work, it just depends on obstructions (eg. trees)
Lee_K_81 Posted January 19, 2007 Posted January 19, 2007 @Ric_ completely agree. Is the changing room attached to the main building, what about a wireless solution for changing rooms? I know they're "jocks" but surely they could come to a solution of writing a paper register and then entering it on to system while the kids change back into uniform? Or they could use their fancy PDA's to write who's there and enter it. Do you really want them running round the astroturf with a PDA in their pocket. Our teachers usually join in the games for a while, wouldnt be long til it broke.
dezt Posted January 19, 2007 Author Posted January 19, 2007 They usually do the register on their pda's and sync them when they get back, but our person in charge of making sure everyone is in lessons gets annoyed when they forget to upload the register. Oh well, if it's too far then never mind. @plexter there is a canal between the main building and the astroturf so a duct would not work. Oh well, looks like they'll have to remember to sync when they do a register.
webman Posted January 19, 2007 Posted January 19, 2007 About the duct + canal.. would some flexible PVC conduit not work for this and just route it parallel to the path that people take to get to the astroturf? Or do they swim across the canal as an addtional exercise?
bishopsgarthstockton Posted January 19, 2007 Posted January 19, 2007 sounds like a political problem between the PE teacher and attendance officer. let them sort it out between them. you probably have enough to do. and if they ask you to come up with a solution, just say "what would you do if computers were not around?" and smile
plexer Posted January 19, 2007 Posted January 19, 2007 Webman: I doubt the school owns the canal or footpath therefore not able to run duct? Ben
Ric_ Posted January 19, 2007 Posted January 19, 2007 @webman: remember that boosting the range of the antenna at one end doesn't help the fact that you have a low gain antenna at the other... wifi is a two-way street.
pete Posted January 19, 2007 Posted January 19, 2007 Your best (wireless + technology solution) bet is a point to point link using a yagi at school and a box with a yagi + omni at the astroturf. If you don't have power, marine solar cells can easily recharge enough gel cells to power an access point or itx board with two wireless cards. Bonus points for Scaramanga-style sun tracking using a PIC, 3 ldrs and a servo. However, we're now in the "fun project" zone. The return on investment doesn't make it worthwhile.
Geoff Posted January 19, 2007 Posted January 19, 2007 Yagi's (or any other directional antenna) are illegal for use with WiFi.
ChrisC Posted January 19, 2007 Posted January 19, 2007 Laser link? Or stupidly expensive repeaters? Chris
plexer Posted January 19, 2007 Posted January 19, 2007 Geoff: Care to point me to some information regarding that statement please? Ben
Geoff Posted January 19, 2007 Posted January 19, 2007 I should qualify what I meant. Using a Yagi on it's own is not illegal but the directed radio energy will exceed 4 watts. Operating a radio transmitter on an unlicensed frequency and exceeding 4 watts of effective power output is illegal.
ChrisC Posted January 19, 2007 Posted January 19, 2007 And isn't it also along the same as the old "power lines are bad for your health" chestnut? Chris
plexer Posted January 19, 2007 Posted January 19, 2007 Geoff: Thats what I thought you were getting at but just wanted to clarify. Of course power of the signal isn't everything quality/noise of the link is more important. Ben
webman Posted January 19, 2007 Posted January 19, 2007 I thought the power restriction is before it reaches the coax and/or antenna? EDIT: here we are .... "In Europe the maximum signal that your antenna can transmit in ANY direction is 20 decibels. This is calculated by adding the wireless device transmit power (in decibels) to the antenna gain (in decibels)" No link to anything from Ofcom, but here it is.
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now