Machare, indeed with two such boxes your devices would just roam between two acting as WAPs providing that you simply interconnect them and set the SSID (‘name of the wireless LAN’) to be the same. I would be inclined to get a dedicated WAP though - which is the same thing without router, modem, firewall, dhcp server etc. The reason being that all that other unwanted junk would just get in the way and some of it would have to be turned off to create a WAP out of your intended wireless modem-routers.
I do exactly this myself but with two WAPs and zero wireless routers. Some WAPs support clever roaming-assist tricks and give faster hand-off times and more intelligent choice of which ‘cell’ (for want if a better word) your device will be in; see 802.11k, 802.22r. Apple devices are reported as supporting such trickery iirc. So if this is correct, some devices will roam better on certain WAPs.
Roaming is all a bit random. Some devices tend to hang on to the WAP that they have been using even when the signal strength gets awful and a cell with stronger signal strength is nearby; you don’t want a device switching from one AP to another all the time because the handover time is significant and causes disruption (especially without 802.11r fast transition). So the ‘stickiness’ of the device depends on its particular o/s. Also the WAP with the stronger signal may not be the best; there may be more interference in that channel and it may be congested with too many stations talking so that it is slow. Some systems kick stations off a WAP if there are too many users, telling them to go to another WAP, and some sophisticated systems send stations to the best WAP for them using complete knowledge of all the important factors.
NB this setup to me is not a ‘mesh network’; that would be something else, something that is all-wirelessly interlinked.
