Over the past 2 years I've written a number of blog entries on Evolved EDGE (here, here, here and here). Now that the feature set is mostly specified, vendors are moving into the implementation phase. A recent whitepaper of '3G Americas' is giving an interesting overview of the different features (without going to much into the implementation details), their potential, and different likely implementation phases. I quite like the paper as it takes a look at EEDGE not only from a technical but also from a deployment point of view.
From a technical point of view the paper mentions one thing in particular which I have not thought about before, and that is that there are two improvements brought by the dual carrier feature. The first improvement is that it improves throughput because timeslots can be assigned simultaneously on two carriers. That's quite obvious.
The second improvement is that even if some timeslots are busy on one carrier for voice calls, the same timeslots on the second carrier might be free and can thus be assigned. This doesn't result in the full theoretical speed but at least compensates for the fact that it is difficult in many situations to have 5 timeslots in sequence available on one carrier. In effect this statistically increases the number of timeslots available for a dual carrier mobile compared to a current single carrier mobile and thus increases the overall speed experienced by a subscriber by using timeslots that could otherwise not be used.