In recent years, due to basic features of MANETs and bandwidth constraint at MAC layer the throughput, delay and maintaining connectivity has been a major focus for research. Here, different issues of MAC protocols and TCP connectivity have been surveyed in detail. Further, channel utilization can be maximized by employing spatial reuse of the wireless channel at the MAC layer. A high throughput MAC protocol called Multiple-Beam Antenna Array MAC (MBAA-MAC) is proposed and analyzed for MANETs. Proposed MBAA-MAC protocol has been simulated to evaluate its performance in terms of throughput and delay under different network topology scenarios. Again, using this protocol, multiple concurrent transmissions are scheduled to improve the aggregate throughput of the network. The conventional MANETs provide communication in a limited geographical area. This was one of the major limitations of MANETs. A hybrid model is also proposed which is a combination of static & mobile nodes. The MBAA-MAC operates on static nodes. A grid topology consisting of chain of nodes has been simulated for different concurrent transmissions