Basically, a wireless router is an access point (AP) with router capability. Sometimes for some reasons you may not need another router to broadcast a network wirelessly. You need an AP and not a wireless router for broadcasting a local area network wirelessly.

Why?

A wireless router has different network ID between it's WAN and LAN connector. That's what routers are for, connecting (routing) two or more different network IDs (in this case: LAN network and WAN network).

For example, I have an ADSL modem to connect to the internet which has LAN network ID 192.168.0.0/24. I want to broadcast this network wirelessly using a wireless router. Fulfilling this purpose is quite easy using a wireless router. Connect modem's ethernet port to the WAN port of wireless router. It's common that the IP address of the wireless router would be automatically assigned by the DHCP server from the ADSL modem. For example, the modem has an IP address 192.168.0.1/24 and the WAN port of the wireless router has an IP address 192.168.0.2/24 assigned by modem's DHCP capability so that both of them able to communicate between each other.

How about the wireless router LAN network ID? It is not possible that the LAN network ID we'd broadcast through the wireless router have a same segment with the WAN network ID. So we would assign LAN network ID to 192.168.1.0/24. Usually, a wireless router also have DHCP server capability to assign it's wireless client IP address dynamically and automatically to match it's LAN segment.

The network would be best described below:

           +++++++                           ++++++                                +------------------+
internet --+ DSL +--- 192.168.0.0/24 --- WAN + WR + LAN/WLAN --- 192.168.1.0/24 ---+ Wireless Clients +
           +++++++                           ++++++                                +------------------+

From the above example, wireless clients had to have a different network ID with the DSL network. So how to make it to have the same network ID between wireless clients and the DSL modem? You need an access point (AP) rather than a wireless router (WR).

So I have a wrong equipment. Do I have to replace my wireless router with (another) access point? If you have a lot of money to spare, go ahead. But, wait, as I said before, a wireless router is an access point (AP) with router capability. You can convert your wireless router to access point with the following simple trick:

1. Disable the router capability on the wireless router, including the DHCP functionality on it's LAN
2. Change your wireless router WAN port IP address to another segment other than the network ID used by the modem (e.g. 192.168.2.254/24) so that it's LAN IP able to be assigned an IP address in modem's LAN segment (192.168.0.0/24).
3. Next, assign your wireless router LAN IP address to anything between 192.168.0.2-254/24.
4. Connect modem's ethernet port to wireless router LAN port (yes, LAN port, not the WAN one).
5. Save the new configuration, and congratulations! you have successfully convert your wireless router to become an access point.

From now on, your wireless client would have the same network ID with the DSL modem. Wireless clients IP address will be assigned by DHCP capability of the modem, and not by DHCP capability of your newly converted wireless access point. The network would be like this:

           +-----+                           +--------+                                +------------------+
internet --+ DSL +--- 192.168.0.0/24 --- LAN + WR(AP) + LAN/WLAN --- 192.168.0.0/24 ---+ Wireless Clients +
           +-----+                           +--------+                                +------------------+

If you found it useful consider to +1 it and/or leave a comment if you had some trouble in converting your wireless router as an access point.