I thought SVDO was a handset implementation? This is from the qualcomm website:
New devices with simultaneous voice and data
.... SVDO changes this by establishing independent voice and data sessions using separate transmit and receive chains in the device.
.... Qualcomm is planning to support the SVDO feature in all of its new EV-DO MSM chipsets.
.....
This is two sided radio system. Not sure why folks keep leaping to conclusion that the "other side" of the system can be completely oblivious to the update.
The MSM chipsets are for headsets/mobile devices not base stations ("towers"). This is clearly a statement about headsets. Yeah sure, you will need new equipment in headsets. However, you need new equipment in headsets to roll out a CDMA/LTE solution also ( capable of separate transmit and receive chains). There is no difference in new equipment requirement.
There is nothing here that says there are zero protocol changes on the base station. Sure, could be situation where can reuse most, if not all, the hardware in the current towers, but if have to roll out a software upgrade then that is an effort. It will also change your network dynamics, so better be sure not going to create as many problems as you 'solve' by rolling it out.
If you have not increased the aggregate transmission bandwidth of the tower then by having phone use two channels instead of one then you just cut the cell's max units capability in half. In crowded cells, you have now introduced crappy service. SVDO is a band-aid ... it isn't a solution. If you have a network of mostly underutilized cells it works much better. Of the list of 38 cities Verizon is rolling out LTE to which one you think is underutilized ?
Even the EV-DO A updates needed tower software updates. Don't see how this protocol update, even if minor and limited to connection creation, gets off with zero updates. Sure as a software upgrade you can roll it out faster than LTE ( which requires software and hardware updates ). However, if it doesn't solve the core problem that is immaterial. Getting the wrong answer fast is not a characteristic of being a good service provider. Also, since can go faster once exited the "test" phase, it doesn't matter much of start later. They can still finished before the targeted LTE rollout is complete.
Rolling out LTE first will decrease the EV-DO data traffic on the cells. Once you have created a much larger network of under utilized cells you can then later flip them to SVDO without crapping out service levels. First though need to roll out LTE and make sure the network goes stable before add another network traffic tweak to the system.
For areas that Verizon will probably not target in the intermediate term with LTE update, they can perhaps roll out SVDO sites sooner rather than later if have personnel and funds to run those concurrently. [***] Those are quite likely under utilized cells so less of a bandwidth problem. They can run that test phase and rollout before LTE completely finishes. However, LTE must get into the "full targeted deployment" phase before start up another "test" phase on another upgrade.
The core of SVDO was designed to be rolled out along with EV-DO Rev B (which would have been an increase of bandwidth). What they have done is strip off the bandwidth increase from the dual channel usage. Yes it makes for a smaller, less invasive, update, but you have also have stripped away aggregate bandwidth utility that it had.
Rolling out SVDO first and LTE second is backwards. All that is going to get you is lots of customers getting crappy service until you get LTE rolled out. AT&T already did it the "dumb" way. There is no need to follow them down that rat hole.
[***] Some cells won't get LTE ( or later) updates for a very long time. All the cell networks spend long periods where they run two core systems. One legacy and a newer one. Most core systems are deployed for at least 10 years.
