Dr. Paul Jacobs, the CEO of Qualcomm, was holding a press conference just now and one of the very interesting questions that he addressed was: “when will we be able to roam from one LTE network from one carrier to another?” This is a reasonable question as LTE network are still relatively thin, and international travelers are very much concerned by inter-operability.
It is not very hard to roam with 3G networks and their HSPA+ derivates because they use a fairly limited number of bands. For example, a phone like the GSM Galaxy Nexus can work worldwide, including on most HSPA+ networks such as T-Mobile, AT&T and others in the world. To achieve this, the Nexus handset is compatible with 5 bands (it is a “penta-band” phone), which is relatively rare. Most GSM smartphones are quad-band.
With LTE, there are even more bands (or radio frequencies) because governments worldwide have allocated “whatever they can find” often without any national or international coordination. Even in the U.S, the LTE networks from AT&T, Verizon and Sprint aren’t necessarily compatible.
People are asking Qualcomm because it has built an empire based on modem technologies, but unfortunately, Dr. Paul Jacobs says that there is not silver bullet. In the short-term, it will be hard to support LTE roaming, but his company is looking at ways to make radios more flexible (to handle more bands). This is really an issue affecting every single LTE modem vendor, and so far, we haven’t seen a universal solution. Let’s hope that future wireless standards will be created with better planning. For more information on 4G networks in the U.S, read our post on this subject.