There's nothing that's reliable in this country lately. MTN is trying but you see Airtel, they can just seem to put off their network at any point in time leaving one stranded. That's why it's advisable to have more than one network source, If Airtel doesn't work, you change to MTN, I can't really recommend Glo because I feel they work only in selected area. Although I heard 9mobile is also good in network connection even if I haven't quite tried it myself. But the network can be really frustrating at times I won't lie especially during that End bad governance protest period, it was as if all the networks planned to work slowly.