Multiple routers & access point setup

Could you please advise to proper router & secondary router setup for my staff building. Our existing connection is as shown on the diagram. However many of users are facing alternative disconnection, slowdown, IP conflict etc. So please advise the best solution for routers IP config & WiFi setting.

I have this broadband and the main wireless router : Main Router Also I have two other routers and would like to make them as access points . So All with the same SSID, then the device can choose the nearest router . Here are my routers . Netgear G Router WGR614 D-Link Dir 619 Both of these are connected by cable, to the main router but I used powerline adapters for the second router as it is far ...
How to use 2 routers with 1 modem (2 Best Methods)

Usually, modern routers scan themselves on all channel bands and configure themselves automatically. Even if the two routers are configured on the same channel, both will scan each other and avoid overstepping. In case there are some problems in the performance of either on multiple access points on the same channel.
After a bit of Googling I found out that it's really easy to create one WiFi network with multiple access points . All you need to do is configure two routers to use the same SSID and password. I picked up an old Dlink DIR-635 router and began configuring it. The first thing I did was disabling DHCP and NAT on the router (bridged).
How to Access a Home Network Router Setup or Console
Step-by-step guidance on accessing your home network router setup or console with simple instructions, tips on IP addresses, and troubleshooting techniques.
Make any additional configuration changes under the Wireless > Configure section of the dashboard network. Be sure to review the SSIDs, Access Control, and Firewall & Traffic Shaping configuration pages. Unpack your AP and attach it to power (via adapter or PoE) and a wired connection with internet access .

How to Set Up and Configure a Router
Learn how to set up and configure a router with our comprehensive guide. Step-by-step instructions for wireless setup , security settings & advanced configuration options.
Before you can access the router's web management page, your device must be connected to the router . The management page does not require an Internet connection, but it does require a connection to the router itself. Option A: Wired connection Connect your computer to one of the router's LAN ports using an Ethernet cable.




