microcell

microcells will no longer work 

Did it work with number sync feature of phones

Numbersync is a software program that allow secondary devices to spoof your phones number for talk and text. Secondary devices would be using data and therefore would be using your home internet connection. 

did it have own wireless feature for iphone to connect through when cell coverage is weak

The purpose of the 3G MicroCell was to create a cell network where there is none, by using your home internet. It is literally a mini tower.

if it checks its location does it appear as if it pinged a phone since it shares the phone sim card imsi

I'm not sure what you mean by this question it doesn't make much sense to me.

The previous Microsoft was a 3G only voice device. While it could be used to connect data as well, it would be rather pointless because the data speed is going to be less than the connection directly through home internet service. Since 3G has shut down the previous MicroCell which was only 3G can no longer function. Since it is tied to AT&T it cannot be used and should be recycled through whatever recycling your town they have for electronic devices

AT&T now has an LTE cell booster which is essentially the same device only the new one which is still a mini tower works with LTE for Voice transmission instead of 3G.

@jacksize  Why do you need to know about the MicroCell? The service is long gone and most, if not all, MicroCell's were disabled by AT&T. If you want to understand how AT&T's femtocells work (MicroCell and now the Cell Booster) see my Cell Booster Technical Guide, the link is in my sig line.