  Data communication in sensor networks can have timing constraints like end to
end deadlines. If the deadlines are not met either a catastrophe can happen in
hard real time systems or performance deterioration can occur in soft real time
systems. In real time sensor networks, the recovery of data through
retransmission should be minimized due to the stringent requirements on the
worst case time delays. This paper presents the application of Stop and Go
Multihop protocol (SGMH) at node level in wireless sensor networks for
scheduling and hence to meet the hard real time routing requirements. SGMH is a
distributed multihop packet delivery algorithm. The fractions of the total
available bandwidth on each channel is assigned to several traffic classes by
which the time it takes to traverse each of the hops from the source to the
destination is bounded. It is based on the notion of time frames (Tfr). In
sensor networks packets can have different delay guarantees. Multiple frame
sizes can be assigned for different traffic classes.
