We build on the framework of joint scheduling and network coding optimization. The formulation is extended to include rate, energy, and delay in network coding and routing paradigms. We then study energy-rate and delay-rate relationships to see how minimum energy and delay change as functions of multicast rate demand. The main observation is that as the rate demand approaches maximum achievable rate, the solution tends to increasingly use more diverse, longer paths. This translates into non-linearly higher energy and delay for higher input rates. In the case of energy, we are also able to show that network coding provides more benefits (when compared to routing) at higher rates. Another observation is related to the scheduling over maximal independent sets (MISs). We present results on comparing the performance of scheduling over all, exponentially growing MISs and small randomly selected subsets of MISs. Our results point to the effectiveness of the latter in achieving near-optimal rate and energy while reducing the complexity of the problem.

The generalized 1+N protection, protects N link disjointly provisioned unicast connections by a single Steiner tree connecting all end points of the connections. By sending network coded packets on the protection Steiner tree in parallel with the working traffic, 1+N is able to recover from any single link failure without enduring the delay from switching to the backup path. This makes 1+N a better protection mechanism in terms of recovery time compared to traditional 1:N and in terms of protection capacity compared to 1+1 protection. Optimal cost provisioning and 1+N protection of a given set of connections is an NP-hard problem comprising of three NP-hard subproblems: partitioning of the connections, finding edge disjoint primary paths and Steiner tree protection circuit for the subset of connections in each partition. In this paper a polynomial time heuristic algorithm for 1+N protection is proposed which combines heuristic steps to address the three NP-hard components of the problem. Our simulations show that the heuristic algorithm provides average cost reduction of 29.2% and 18.5% compared to 1+1 protection in COST239 and NSFNET networks. An asymptotic bound is also derived for the case of complete graph networks which shows that 1+N can achieve maximum of 66.6% cost improvement compared to 1+1. When compared to the optimal 1+N solution from ILP formulation, the heuristic algorithm increases the cost no more than 13%.

Increasing use of commercial off-the-shelf (COTS) superscalar processors in industrial, embedded, and real-time systems necessitates the development of error detection mechanisms for such systems. This shows an error detection scheme called committed instructions counting (CIC) to increase error detection in such systems. The scheme uses internal performance monitoring features and an external watchdog processor (WDP). The performance monitoring features enable counting the number of committed instructions in a program. The scheme is experimentally evaluated on a 32-bit Pentium/spl reg/ processor using software implemented fault injection (SWIFI). A total of 8181 errors were injected into the Pentium/spl reg/ processor. The results show that the error detection coverage varies between to 90.92% and 98.41%, for different workloads.