Wirless LAN Deployment

It's hard to answer this question without knowing additional information:

How big is each floor (sq ft)
How is each floor laid out; e.g. rectangle/square L shape
What is the construction of the building?

4 th floors 4 access points ( 4 wireless hub) is enough normally Think it as a hub wired netwrok.

Yeah i can understand that it depends on the building & size.
Assuming i require 2 devices per floor  is it required to have a central controller to manage all these wireless access points.

Also let me know is there any mechanism or any procedure to check & ensure how many devices are required per floor. On what basis i need to check & ensure that i have the right  no of wireless access points & the signal strength is good.

if you have auto cad diagram for the same then any OEM of wireless such as aruba, rukkus can provide you the heat map and AP quantity.

 or else you can ask system integrator or wireless vendor..who can do the survey or POC on behalf of you.
 else if you have any wireless AP with you..you can do the survey upto a certain level.

design should be...floor to floor back bone connectivity with UTP cable(cat6/cat6A) or of floor to floor distance is more than 90 mtrs then it should be with fiber connectivity.
if you required fiber BOM.....that i can provide.

there are certain things that needs to be take care:-
1. wall width
2.glass door is there or not
3. obstacles
4.any other radio frequency is working on that channel or not etc.

please revert...for further clarification

Diprojbasu has some good points.    I am in the beginning of a convention center project.  I'm using Aruba equipment there.   They took the floor plans and providedme with a heat map.   They even reduced the number of APs I thought I was going to need.

I would definately look at using a controller for your environment, if not more than to just simplify managment.   You want to go with professional equipment.

Watch to make sure that you assign your channels to minimize interference.

Wireless deployements nowadays is not about coverage - sorry.
Coverage is of course important - but more important is:

- How many users will you have?
- What services do you offer?
- How will users authenticate?
- Then some coverage - performance

Coverage is easy - you have poor coverage - install another AP or 2 -- it's as simple as that.
When it comes to the design, think about this.

Amount of users:
- thinking this will be corporate users, they would probably use this for both intensive application (virtual desktops, file sharing, database applications) and somewhat critical applications that needs to be online - when they should be online :-)
- Then design wireless with at leat 50% "over-coverage" so one AP could go down, while the nearby AP's can cover that area. You should try to keep number of users around 20 - 40 users per AP - depending on which AP's you buy - and, as mentioned, what applications you should run.

What services should you run?
- Most likely users will come running with iPads, Smartphones as well as computers. Expect Music and videostreaming, Skype and possibly Lync video and voice calls, Citrix, File sharing, Dropbox, web pages and more. Either deploy enough APs to support this (preferably with QoS), or shut down services available - in firewall

Authentication
- Never (!!!) deploy a corporate network using PreSharedKeys. They can be broken, but most likely they'll leak. Once you give the key to one or two users, they give it to other, write them down and you will have no idea on how many know your (secret) PSK
- You should deploy 802.1X with mixed computer and user authentication, if possible with certificates - or using domain usernames and passwords. That way, every wireless client will have it's own randomly created encryption key - which changes regularly. A sniffer will never get enough packets encrypted with the same key to be able to hack it.
- 802.1X would be another story - but there's a lot of good guides out there

Coverage/Performance.
- deploy 802.11n and make sure you either lock it to 802.11a/n, or do radio tweaking in wireless AP's/Wireless Controller to "force" clients to use 802.11a/n rather than 802.11b/g/n. This is because 802.11a/n use 5Ghz band which has several more non-overlapping channels, and also have less interference from "non-802.11 devices"
5Ghz have shorter range, but you can get increased performance using that.
(note: 802.11ac - the new Gbps wireless standard only uses 5Ghz)
- make sure all clients get good coverage - as the slow clients with low signal strength will slow down those with good strength


When it comes to equipment, I mainly work with Aruba Networks - worth looking into

Thanks