Wireless networks, for distributed control systems in general and interactive power networks (IPNs) in particular, demand a fresh look to minimize communication delays and improve throughput performance, while transmitting data having size on the order of few bytes. Using variable packet length time division multiple access (TDMA) approach at the medium access control (MAC) protocol layer we propose a merged-packet routing (MPR) algorithm at the network layer for an all-to-all broadcast to improve the throughput and delay performances. Taking into account the effect of channel noise we show that the idea of packet merging provides noticeable performance gain for the throughput without compromising the delay. The delay performance is further improved by adjusting the transmitter power according to the packet length.