HSDPA Tsunami

I have just returned from CeBIT, where HSDPA along with HDTV were the hot (and real!) trends. OK, first let's explain these acronyms. HDTV stands for High Definition TeleVision and means better than cinema picture quality - I'll probably write some more on HDTV later, but for today let's focus on HSDPA. High-Speed Downlink Packet Access is the full name of the technology that is rolling like tsunami over mobile telecom networks. You've probably already heard of UMTS - the 3rd generation mobile telephony that was heralded in 2000 and for five years existed as a pure vaporware. Now UMTS is here, and we use it for high-speed (sort of...) wireless Internet access and video calls among other things. But probably not many of you are aware UMTS that took so many years and billions of $$$'s to become real is about to be replaced by HSDPA. OK, it does not look that bad as it sounds. HSDPA is an evolution of an UMTS standard, namely Release 5, defined in March 2002. Its main feature is enhancement of the connection speed by an order of magnitude. 3,6Mbps in current implementation, with theoretical limit at 14Mbps. That is 100 times faster than current GPRS data links, most of you use for email and Web browsing when on the move. The implications of this technology are endless. It will bring you the joy of fast Web access via your mobile phone. It will allow to download a high quality MP3 song in a matter of seconds. And it will make other mobile data technologies, notably the hyped WiMax, obsolete.

From the technology standpoint, HSDPA is a series of very logical optimizations to the UMTS (W-CDMA) technology.

• Fast Scheduling. Most of the speed limitations in over-the-air transmissions come from the noise and corrupted data packets being received by the handset. When a corrupt packet arrives, it has to be retransmitted again. In traditional UMTS architecture the decision to retransmit is taken by the RNC (Radio Network Controller) and takes time. In HSDPA the retransmission decisions are taken by the Base Station (the tower with antennas, your mobile talks to), that sits much closer to the handset, and are much faster.
• Incremental Redundancy. It may happen the second (retransmitted) packet arrives corrupted again. But it may be corrupted differently than the previous one. And by combining two such corrupted packets the handset may reconstruct a good one, without a need of further retransmissions.
• Channel Quality Feedback. The base station listens to the handsets that report the channel quality. Statistically the conditions vary as users move, and it is very reasonable to transmit packets to the users who have the best reception quality at the moment (the chance of having to retransmit is low). This is done 500 times a second, so any of the 2ms packets can go to a different user, depending on the momentary channel quality.

There are some other technical details into HSDPA, but two things should be stressed here. First, HSDPA is just a software upgrade for any UMTS network. No need for new base stations. No need for new towers. Just apply the HSDPA patch and go! Second, overall throughput of HSDPA network is several times higher than UMTS network, so this means more users can be served at a time, and ultimately the cost per minute/megabyte goes down. Tha simply means HSDPA, if not already here, will be deployed sooner than you expect. The upgrade is realtively simple and the business benefits are here.

And now comes the real fun... Are you aware there is only one company on the Planet that makes commercial HSDPA chipsets for handsets? Yes, that is true, only Qualcomm has shipping chips. All the competition is about a year behind. That means if you come across a HSDPA handset or a smartphone, it is Qualcomm-based. Qualcomm's MSM6275 has been available since Q4-2004. Freescale (former division of Motorola) promises something for Q1-2006, but we already know its mother - Motorola - rejected the chipset for its size (does not fit in the thin RAZR enclosure) and turned to Qualcomm. Texas Instruments (probably in cooperation with Nokia) says "wait until 2007". Probably the closest competitor is Ericsson Mobile Platform V350 scheduled for 2H-2006. Are you invested in Qualcomm? It has just hit its multi-year high of $51. But HSDPA, among other things will drive it to the new highs.