Sunday, July 3, 2011

Why wait for 4G?

Too many people start to jump on the hype of 4G, while there are still all the options in the world to improve on the current technologies in the 3GSM (or just 3G) family. Therefore, I thought it would be good to explain briefly here some of the concepts that can improve the networks. In Latin America, many networks are still clearly inferior to their European sister networks, even thought they use the exact same equipment. Differences in the installed capacity is a good part of the reason, but network optimization and improved radio planning can also make great contributions to an improved quality and capacity.

When I was taking a ride on the rapid train from Madrid to Barcelona earlier this year when I was at the Mobile World Congress, I enjoyed a fantastic experience with about 1,5 Mb per second bandwidth on about 85% of the train-ride  This experience was so much superior to what is offered on a flight, not to mention that the 3 hour trip goes from downtown Madrid to downtown Barcelona with no long check-in or baggage pick up queues. From when I took the handle of my suitcase at the Hall 6 in the far end of the conference area, till I sat on the train it took me 25 min, and I walked all the way to and from the metro. But, that's another story.

This, today done with 3G, and can be done in Latin America with the same 3G equipment also. The Air is the same, right? And the equipment is already there.

Over the last few weeks I have participated in various events, discussing broadband and the mobile Internet access, and I keep hearing questions about when will 4G get here, so we can get a better service. In my opinion, the ones who are waiting for 4G are wasting their and our time, as there is so much that can be done now: MIME, 64QAM, Multiple Carrier, are all general upgrade features for the HSPA networks, but there are also more to do: Heterogeneous Network, or HetNet, is used to designate a radio cell planning concept where large macro cells and small low power pico-cells are making up a much more efficient network, which can gain in both quality and capacity. In many cases even without demanding more spectrum.

The gain in quality comes from the shorter distance between the handset and the base station. The handset transmits with a much lower power than the base-station, so if the distance is too long, the up-link from the handset to the base-station looses quality due to interference.

The gain in capacity comes from the fact that smaller low power cells gives little interference with the large macro cell even if it is transmitting on the same frequency. The mobile network can therefore serve more handset in the in coverage area of a macro cell without actually loading the large cell and its base-station. The traffic is simply handled by the small low-power pico-cells.

In  both cases, the small pico-cells can be served by so called Remote Radio Units (RRU), which can coordinate the power and inter-working of the cells in order to increase efficiency. *)

Conclusion: There is no reason to sit down a wait for 4G, but all the good reason to get going a with 3G network optimization.

*) Ericsson's concept covering this new small radio units is called AIR (Antenna Integrated Radio), and is a small box with antennas build in, which can be placed directly on building walls in shopping malls for example.
General information in article
The Magazine Ericsson Review on the topic