Dongle Upgrade Incentives

Here's a thought experiment about whether and how operators should encourage users to upgrade their 3G dongles to a newer model:

Most HSPA dongles currently 'in the wild' are are HSDPA category 6, i.e. they are capable of theoretical speeds of up to 3.6 MBit/s. Category 7 dongles with a maximum theoretical speed of 7.2 MBit/s are now also available and currently going over the counter. The speed increase between the two is mainly due to an increase of the number of spreading codes the device can handle simultaneously. In other words, from an overall network capacity point of view it does not matter a lot whether most of the devices used for high speed Internet access are category 6 or 7. In the future however, this is going to change.

Pretty soon, higher speeds in HSPA networks will be mainly achieved by more sophisticated 3G devices and networks. Receive diversity with several antennas helps during weak signal conditions (this Ericsson paper is a good starting point for further research) and MIMO while reception is good. In addition, more sophisticated mathematical approaches to separate noise from useful data will also help to increase data speeds. From a network point of view, this means that the more of those newer devices are in the network compared to the number of older devices, the higher the overall throughput of the network.

So should it be in the opreators interest to encourage users to upgrade to newer devices? And if so, how could that be done best? Is the higher speed achived with those devices incentive enough or should the base station scheduler also take the UE category into account to further boost data rates of newer devices? I could also imagine to offer a reduced rate to users with newer hardware as they use the air interface more economically than users with older hardware. Kind of a similar approach to taxing older cars with higher emissions higher than new cars (don't take the analogy too far…). Or maybe this is all overkill and the normal equipment replacement cycle of 2-4 years will do the job anyway!?