Follow Slashdot stories on Twitter

 


Forgot your password?
Close
typodupeerror
×
Technology

Wireless Networks in Metropolitan Areas? 12

Posted by Cliff from the this-won't-hose-my-WKYS-in-the-morning-will-it? dept.
Lomby asks: "I am networking a company that has two offices in the same city. Clearly they would like to exchange data between them. Since I live in an internet under-developed country (Switzerland), a permanent cable connection is out of question due to the high costs. The most obvious choice is to connect the two offices via ISDN, but this has the drawback of cost per time unit, and the connection would be estabilished only a few time a day, bringing consistency problems. Now I'm looking at a wireless solution: has anyone tested a wireless system in a metropolitan area (10 km)? Costs? Problems? Field of view? Works with Linux? Do I need to install a huge antenna? "
This discussion has been archived. No new comments can be posted.

Wireless Networks in Metropolitan Areas? More

Wireless Networks in Metropolitan Areas?

Comments Filter:
  • Dear Sir,

    I wish to flame you and/or believe that you are in fact a "Karma Whore", as the saying goes.

    Respectfully yours,
    A. Troll, Esq.

    [*af*]
  • Same city ... both LANs?

    Does the local phone company have ATM?

    Does the local phone company have ADSL/DSL?

    Can the local phone company provde both locations the services ATM or DSL?

    What are your bandwidth (LANs size and applications [email, VTC, ...]) requirements?

    What can you afford (to pay the local ..., not me)for the solution?

    If you're a small company then ADSL may be your best option.

    If you're a very small company or just some geeks putting together a network for kith and kin then a MultiLink PPP connections 56K dialup technology tandem/parallel modem bank like the Diamond products "http://209.10.46.176/default.asp?menu=suprasonic_ II&sub_menu=&item=" Technology (with two 56K modems you could maybe attain up to 112Kbps downloads), and just connect multiLink modems when you need LAN to LAN connectivity.
    I don't look at ISDN anymore as a communications solution ... ISDN and PPP is sometimes the only option provided in an area.
    Why ATM, because with an ATM backbone access at bothe LANs, switched LANs/Routers/Hubs to an ATM backbone, and Ethernet infrastructure (cables/connectors/...) data delivery latency for even VTC may not be a major factor (eliminating ISDN drops/requirements).
    Why ADSL, well depending on the local cable/phone company owners' policy (and government regulations) you could do an ADSL link to control bandwidth cost (ADSL provided bandwidth at about 11 times ISDN 128K and for about the same price, maybe a little more).

    So! The big question is what can you afford in bandwidth, and will that bandwidth fulfill customer applications requirements for a few years? If not (for any reason, and after talking to the local phone companies' folks) ask for more money for your project.

  • I had a friend who worked in a building that was networked to the next building over via 2 methods:

    • Microwave - This worked fine, at i think about 100kbit to 1Gbit speeds
    • Infrared Laser - This SUCKED. It had the capablility of multi Megabit bandwidth. The bigwigs wanted it because, "Hey we have a LASER link between buildings." Well, there is a big problem, the system was a narrow beam. If there was ANY wind or seismic activity, the beam lost alignment and zero throughput. If there was Fog or rain, the bitrate DROPPED.

    therefore, the microwave link was aways up and running at ~300Kbit and the laser ran at 100bit/sec except for bursting to 1Gbit about 3 times a year for 30 seconds :-)

    A wealthy eccentric who marches to the beat of a different drum. But you may call me "Noodle Noggin."

  • if you have point of sight between the two buildings you can set up a wireless backbone rather easily. Maxtech makes some pretty good equipment for such a thing, or check out these guys [com-pair.net], they do what your looking for.
  • I've been looking into wireless technology for the past few weeks. I am more interested in what it takes to set up an wirless ISP that may have thousands (if not more) users (especially useful for thrid-world metropolitan cities). How would thousands of 'radio modems' (probably spread spectrum type thing) interact with a single hub (or a set of hubs throughout the city)? Exactly what kind of capabilities would these 'hubs' need to have? What kind of costs are involved...must get information....
  • I have heard a lot of about this recently Highlights Enables wireless non-line-of-sight connectivity Delivers up to 44-Mbps full-duplex throughput Cisco IOS software support and management via Cisco IOS command line interface (CLI) or CiscoView Each line card supports two antenna systems for spatial diversity Supports multiple frequency bands through a common interface Supports 10 MHz reference here is the link for more info... http://www.cisco.com/warp/customer/cc/cisco/mkt/se rvprod/wt2700/ubrmc_ds.htm you said ISDN was pricey you may want to see if centrex priceing is available. you conference call the other isdn device, or something of that nature, in pa it is 10 bucks a month for unlimited calls to that other single location, both sites must be centrex, I am sure somebody else can provide more info.
  • Wireless can and can not be a viable solution in a metropolitan area. Huge towers are not needed depedning on the line of site issue. Being a wireless tech I can really recognize the benefits and costs of a wireless system. Point to Point of up to 50 mi is quite easy with existing Lucent equipment but once again that line of site issue is the major downfall. There are easy ways around this with relays or a nice omni directional field that will cover maybe 5 mi or more depedning on amplification.
  • The longest distance I've ever tried was about 3km using equipment that's a year or two old so your results may vary. Anyway to get back to the subject, LoS considerations are quite important even though microwave or RF systems don't technically need for there to be a clear visual path. If you don't have a good LoS between the receiver and the transmitter, you are at the mercy of wave piping effects and greater potential power dispersion/interferece. A directional system is definitely better than omnidirectional systems, but they are slightly harded to set up. I don't know about any special conditions that a metropolitan area might impose, although a reasonable guess would be the greater saturation in noise level might require more transmitter power.
  • May I direct you to a company which specializes in wireless routers/brides and highspeed modems (1.5Mb/s). The company is Waverider Communications based out of Canada. They specialize addressing these types of situations. They are just starting to really rollout their line of products which is why you may not have heard of them, but check out the website and/or send them an e-mail and you may be pleasantly surprised.
  • The Url for Waverider is http://www.waverider.com
  • Good topic! Are you just wanting to eval/choose commercial products? Check out these products and links. http://hydra.carleton.ca/info/wlan.html There are lots of free-range solutions to sort thru, for example http://www.tapr.org/ Steve Stroh writes the wireless column for Boardwatch http://www.boardwatch.com -Go read those, they are full of information, steve is at strohpub.com Todd gldialtone.com

Slashdot Top Deals

The use of money is all the advantage there is to having money. -- B. Franklin

Close