Table 3 Comparison of the main characteristic of various TCP Enhancements
From: TCP performance in multi-hop wireless ad hoc networks: challenges and solution
| Â | " TCP-DDA " | " TCP-DAA " | " TCP-DCA " | " TCP-ADW " | " TCP-MDA " |
|---|---|---|---|---|---|
| Â | [39] | [41] | [43] | [44] | [45] |
DEALING WITH ROUTING FAILURES | No. | No. | No. | No. | No. |
DEALING WITH WIRELESS ERRORS | No. | No. | No. | No. | Partially: the setting of delayed ACK is based on the information collected from the channel; this may reduce the effect of wireless errors. |
DEALING WITH CONTENTION | Yes: reducing the number of ACK may reduce the effect of contention. | Yes: reducing the number of ACK may reduce the effect of contention. | Yes: reducing the number of ACK may reduce the effect of contention. | Yes: reducing the number of ACK may reduce the effect of contention. | Yes: reducing the number of ACK may reduce the effect of contention. |
DEALING WITH RETRANSMISSION | No. | No. | No. | No. | No. |
DEALING WITH TCP CONGESTION CONTROL MECHANISM | No. | Yes: cwnd is limited to maximum of four packets. | No. | No. | Yes: cwnd is limited to maximum of four packets. |
DEALING WITH HIDDEN EXPOSED PROBLEM | No. | No. | No. | No. | No. |
DEALING WITH TCP RATE | No. | Yes: the rate of TCP is limited due to cwnd limitation. | No. | No. | Yes: the rate of TCP is limited due to cwnd limitation. |
DEALING WITH TCP ACK | Yes: it delays the ACK for a maximum of four packets. At the start up, it reduces the delayed ACK to one. | Yes: it delays the ACK for a maximum of four packets. In the case of packet lost, it reduces the delayed ACK to one. | Yes: it delays the ACK adaptively based on the number of hops. | Yes: it delays the ACK dynamically based on the transmission rate, loss event, and number of hops. | Yes: it delays the ACK based on the feedback from the MAC layer. |