Multiplexing Gains under MixedDelay Constraints on Wynerxe2x80x99s SoftHandoff Model This paper analyzes the multiplexing gains (MG) achievable over Wynerxe2x80x99s softhandoff model under mixeddelay constraints, that is, when delaysensitive and delaytolerant data are simultaneously transmitted over the network. In the considered model, delaysensitive data cannot participate or profit in any ways from transmitter or receiver cooperation, but delaytolerant data can. Cooperation for delaytolerant data takes place over ratelimited links and is limited to a fixed number of cooperation rounds. For the described setup, inner and outer bounds are derived on the set of MG pairs that are simultaneously achievable for delaysensitive and delaytolerant data. The bounds are tight in special cases and allow us to obtain the following conclusions. For large cooperation rates, and when both transmitters and receivers can cooperate, it is possible to simultaneously attain maximum MG for delaysensitive messages and maximum sum MG for all messages. For comparison, in scheduling schemes (also called timesharing schemes), the largest achievable sum MG decreases linearly with the MG of delaysensitive messages. A similar linear decrease is proved for any coding scheme, not only for scheduling schemes, if only transmitters or only receivers can cooperate (but not both) and if delaysensitive messages have moderate MG. In contrast, if the MG of delaysensitive messages is small, the maximum sum MG can be achieved even with only transmitter or only receiver cooperation. To summarise, when cooperation rates are high and both transmitters and receivers can cooperate or when delaysensitive messages have small MG, then transmitting delaysensitive messages causes no penalty on the sumMG. In other regimes, this penalty increases proportionally to the delaytolerant MG in the sense that increasing the delaysensitive MG by    xcex94    penalises the largest achievable delaytolerant MG by     2 xcex94     and thus the sum MG by    xcex94   .

Capacity of Wideband Multipath Fading Networks with Physically Degraded Broadcast In this work we investigate the capacity of multilayer relaying networks operating over multipath fading channels under a noncoherent wideband regime and physically degraded broadcast stages. First, based on hypergraph models and network equivalence techniques, we derive an upper bound on the network capacity. Then, by considering a peaky, frequencyshift keying signaling scheme, we establish a set of pointtopoint achievable rates for each communication link in the network. Finally, by capitalizing on this set of rates we devise an achievable transmission scheme for the entire network via network coding. Remarkably, it turns out that this achievable rate for the network coincides with its upper bound capacity. In other words, these results give ultimately the capacity of the investigated network.