With Clearwire now having officially announced that they will be using the TDD flavor of LTE in the 2.6 GHz band it once again becomes very clear that the strategy of US carriers is to require tailor made devices even on the LTE side of live.
Not that Clearwire could have also chosen the FDD variant of LTE in that band which is already used in Europe by ALL carriers in the frequency band with all the spectrum they are sitting on. I fail to see the advantages of that for everybody involved, the carriers, the device vendors and the customers.
On the one hand, carriers depend on manufacturers to produce specific devices for them so I wonder in what kind of bargaining position that leaves them in. On the other hand, device manufacturers can't get a similar economies of scale for custom made devices than for devices they sell in regions such as Europe, where all carriers use the same set of frequency bands. Unless of course they start building multi-radio-mode devices for the US as well that work across different technology and frequency ranges. Not impossible but I haven't seen one yet.
Let's compare: A future LTE device for Europe has to support the following frequency ranges and technologies:
- GSM in 900 and 1800 (+850 and 1900 MHz for US roaming)
- HSPA in 900 and 2100 MHz (+850, 1900 MHz for US roaming (+1700/2100 for T-Mobile US depending on the outcome of the AT&T merger))
- LTE in 800, 1800 and 2600 MHz (+ roaming?)
That's the setup and applicable for all network operators in Europe, including global roaming to the US and Asia, including China.
And here's the list of bands/technologies for a device that would support all carriers in the US in a world without the merger of T-Mobile US and AT&T. Such a device would give the consumer the choice to pick the device and the network operator independently in the same way as in Europe:
- CDMA in 850 and 1900 MHz for Verizon and Sprint and other small CDMA carriers
- GSM in 850 and 1900 MHz for AT&T and T-Mobile
- HSPA in 850 and 1900 MHz for AT&T and T-Mobile
- HSPA in 1700/2100 MHz for T-Mobile (without the merger with AT&T, who would probably put LTE in here perhaps rather sooner than later).
- LTE in 700 MHz for Verizon
- LTE in 700 MHz for AT&T with an upside down uplink/downlink compared to Verizon
- TD-LTE in 2600 MHz for Clearwire
- ??-LTE for Lightsquared
- + a couple of roaming options for devices to remain usable outside the US when people travel.
Technologies and frequency ranges are very different between the operators, which is probably the main reason devices don't exist today that span the whole range of network operators. Modern HSPA devices support all three US HSPA frequency bands and in addition the two HSPA bands of the rest of the world so they can at least be sold to AT&T and T-Mobile without modification. But fast forward two or three years and AT&T will require devices to have their 700 MHz LTE band included and in addition perhaps another band such as the 1700/2100 MHz band for LTE should the merger with T-Mobile go through.
In Europe we've had the freedom to select the devices and networks independently since the start of GSM two decades ago. I just can't get my head around a system in which this is not the case and thus severely restricts the choice of consumers and competition.
The only thing that would help to reduce the negative effects of the world having been unable to assign and use the same spectrum ranges and technologies would be a universal radio module adapting itself to whatever it finds in the air. But from what I can see there's not even a prototype of such a thing on the horizon.