A very attractive alternative for communications in areas in which there is little or lack of backbone telecommunications infrastructure is to use Multihop packet radio networks (MPRNet:s). One major design issue in MPRNets is the formulation of Medium Access Control (MAC) protocols. Spatial TDMA (S-TDMA) is a conflict-free multiple access for MPRNets, which ensures that a packet transmission, whenever made, is successful. S-TDMA is a link oriented scheduling. The availability of variable data rates in wireless radio networks raises the problem of controlling them in the most spectrally efficient way. In the radio channel, transmission rates are related to the Signal-to-Interference Ratios (SIRs), and the SIRs can be efficiently controlled by transmitter power. Therefore, it is natural to associate rate control with power control, which by be investigated in this paper. The multihop ad hoc networks studied in this paper consist of a collection of twenty nodes, which have been randomly dispersed over the given area. We considered stationary networks with the nodes equipped with omnidirectional antennas and using a single frequency for the whole network. In order to build the S-TDMA schedule, we enabled a set of radio links, for each timeslot, that fulfill two conditions: a) They are prioritized accordingly to their traffic load and b) The SIRs commonly used as a measure of the link quality, is above certain thresholds named SIR target. In latter item power and rate control can be used so that the number of successful transmission will be maximal. For sample networks, we have got some results by means of discrete even simulations. A new scheduling algorithm, PR S-TDMA, STDMA with power and rate control included significant improves network performance in MPRNet:s. The simulation results show an improvement average delay and the maximum throughput, for all traffic conditions, in comparison with the traditional S-TDMA.