Geographic requirement for network?

it is only important if you have more than one location...so you can plan on how the WAN will connect...for wireless, you need to do a 'site survey' so you can determine if you have line of site between attennae...

There are physical limits for both types of networks.

For a wireless network, you need to plan the nodes to provide just enough overlap in coverage so that all users can connect.
You also want to avoid placing nodes in locations that will allow un-intended access to your network.
If you keep the signal from reaching the parking lot or a nearby building, you improve your security greatly.

For a wired network, there is a maximum length of cable that can be run between routers.
You also want to plan for the number of users and data transfer requirements for each router.
If a high data volume application is at the end of several chained nodes, all users along the path can have slow connections.

Chas

I know, in my campus, signal is blocked in some buildings, and I know that isn't the purpose of the designer, so why this happen? What should be done to solve that? And in the wired network, if the distance between two buildings is longer than the maximun length of fiber, what should designer do usually to connect the two buildings? Thanks

Extending connection length can be done by either changing the connection type, ie switch to microwave or fibre optic (if they are so far apart that it is outside the length of T1 fibre optic you should consider satellite dishes), or just install some repeaters along the cable.

To get around a comms problem due to an intervening building, you can either route the link via another building, or set up a router to relay in that building, or change you link type; eg satelite link over it, or cable to the building beside it, or microwave to the roof and off again.

Another aspect of the geographical is that it is best to set up each demographic area (this covers physical work and logical work areas) as seperate local area systems with a link to the rest. You do NOT want the one switch to be trying to manage users in to different buildings or floors if it can be avoided, nor do you want to run an excessive amount of cable runs between areas or around building.

Ideally you have a switch in the middle of each floor with runs for everything on that floor (larger arrangments may require a number of switches on a floor) and it has one run that connect to a router or switch which manages the building and this has one run that connects to the next router or the main system router, etc.

Good understanding of the geographical arrangement can allow you to set up with the minimum amount of hardware and installation cost.