Unstrung has an interesting pointer to Verizon's first draft spec (v0.9) which details what they want devices to be capable of to allow them on their future LTE network. While they are mainly referring to relevant 3GPP specification documents, there are some nuggets of information in there that took my attention:
- The 700 MHz band they intend to use seems to be band 13 in 3GPP talk. I wonder if that encompasses the complete 700 MHz band in the US or just a part for it!? In other words, will band 13 devices also be usable in other LTE networks (e.g. that of AT&T)? According to this post on Gigaohm, the total bandwidth of the 700 MHz that was auctioned off was 18 MHz per direction (uplink/downlink), so the answer is probably yes.
- The channel bandwidth they will use: 10 MHz (double that of HSPA today but short of the theoretically possible 20 MHz as per the standard. Again, by looking at the link above, that's obvious because that's all there is available.
- Devices must have RF connectors for testing purposes for all antennas. Haven't seen that in years on mobile devices. RF designers will have fun...
- Devices will be assigned an IPv6 address when attaching to the network. IPv4 addresses shall be requested by the device if an application requests an IPv4 connection. The IPv4 address shall be released once no applications are executed on the device that require it. Interesting requirement, looks like an IPv4 address is not initially assigned to the mobile device by the network. This should not be a big deal, S60 for example already has a dual IPv4/IPv6 stack today.
- Mobile device timer for moving from Connected to Idle state: The document says that the LTE standards say that the move from Connected to Idle state (on the radio layer, this has nothing to do with the IP address assignment) is controlled by the network. The standard leaves it open for the mobile to also initiate such a state change, for example if the device detects (by whatever means) that no applications currently wants to send and receive data. At this point, however, Verizon does not mandate devices to implement this. An interesting side note: Today, HSPA only knows a network initiated state change in the standards. In practice, however, there seem to be some devices that also trigger it from the devices side with a bit of an unorthodox signalling message exchange. Looks like standards people have learnt from that and included this feature in the LTE specs from day one.
- No mention is made of dual mode CDMA/LTE capabilities. I wonder if that means that they expect that first devices will be LTE only? That wouldn't make a lot of sense to me. I can't imagine people would be very happy using a CDMA USB dongle and a separate LTE dongle, depending on where they are.
- Verizon expects that first devices are data only, no voice capabilities. A pity, but who knows, they might yet discover the benefits of VOLGA.
Note that the current version is only a draft, there are still many unfinished chapters.