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EvDO High-Speed Wireless vs. 802.11
willll writes "The Washington Post is running a story about EvDO (Evolution Data Only), a high-speed wireless technology. It can work anywhere that a mobile phone can work, one of its main advantages over WiFi. Companies such as Verizon and Lucent are looking into the technology." From the article, I'm not sure that EvDO can be directly compared to WiFi connections (and the article does not mention current long-range 802.11 ISPs), but it's still interesting.
This is a lot like CDPD (Cellular Digital Packet Data), which was supposed to work over existing AMPS networks. It had the same basic problems - you had to update the cell site to make it work, and the cell carriers had to set aside some bandwidth for it.
However, unlike when CDPD was first rolled out, there is now a demand for such services....
www.eFax.com are spammers
One of the nice thing about CDMA in general is that you can be moving at high way speeds and maintain a constant connection through what's called a "soft handoff", where you receive data from both towers as you transition from one to the other. There are sprint users who's actually surfs the web while in moving at highway speeds (as the pasenger, of course :)
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In Europe, "3G" (third generation) technologies were supposed to transform the economy, turning cell phones into mini-entertainment centers, but reality failed to live up to the hype.
Its difficult to say that '3G' or UMTS to be exact has failed in Europe, as most have not yet launched due to the financial strife in the telecoms sector limiting investment into the new infrastructure. In fact Hutchinson's Three (UK's first UMTS network) will be going live soon
Granted this pressure has resulted in GPRS '2.5G' becoming more widely adopted, and this can provide many of the benefits of UMTS as far as the user is concerned such as reasonable speed mobile data access, whilst being a step upgrade to the GSM netwrok so cheaper to role out and not needing thousands of new masts (UMTS needs masts in different physical locations as it uses a different radio system - see later)
In this respect Europe is in a more fortunate than the US as GSM digital cellular networks have become the standard, so the upgrade to GPRS is a logical one.
The growing interest in EvDO adds to the momentum of Qualcomm's CDMA (Code Division Multiple Access) standard that is now used by some of the largest wireless companies, including Verizon and Sprint Corp
This is a strange tack to take, given the dismisal of '3G' as a failure a few lines before.
In Europe the new standard chosen to replace GSM was UMTS, which is based on a CDMA radio sub system. This is a spread spectrum method which brings many benefits, but means you need new masts as the radio coverage is different.
In the US you have Qualcomm's CDMA 2000 system which will evolve into the W-CDMA standard
In practical aspect these are equivalent systems, at least as far as the radio engineering goes - the differences mainly being in how the networks are run and how data is transfered, the underlying carrier technology is very similar, and infact most of the equipment is the same, differing only in the management systems.
So in Europe the delayed roll out of UMTS can be seen really as a factor of the depressed state of the telecoms market, and the fact that the cheaper to roll out GSM based GPRS system gives you high speed data access.
In the US there is no easy upgrade from an existing network as GSM didn't make much of an inroad and the better range in fringe areas of analogue systems like TACS is more suitable to the larger country.
Realistically the only way for the major equipment providers to realise the return on investment of thier CDMA technology is to go after the one thing the alternatives don't do well, the domain of large scale wireless data access.
The 1xEV-DO forward link rate ranges from 38.4kb/s to about 2.4 Mb/s. The reverse link ranges from 9.6kb/s to 153.6 kb/s. Both rates change dynamically according to what the link can support. The overall capacity is greater than IS-95 because stronger error correction coding is used.
The Qualcomm website has quite a bit of detailed technical info. See http://www.qualcomm.com/cdma/1xEV/.
The Data Only (DO) version the article talks about needs its own carrier freq, so the providers must set aside valuable spectrum for data only services (read: expensive). Since none of them can seem to spare the money or the bandwidth at this point, I don't think anyone is eager to implement it, even though the equipment already exists to deploy it.
:)
What will be interesting will be the DV (Data-Voice) standard, which can carry both data (up to 5Mbps) and voice at the same time in the same spectrum used by current 1xRTT and Ev-DO channel. I believe SprintPCS has already decided to skip over DO and go straight to DV, sometime around 2005 when the base station equipment and handsets will become available. It might even happen sooner, if Qualcomm feels pressure from GSM/EDGE/WCDMA camp.
Let the wireless web wars begin
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Well, 1xEV-DO isn't faster than WiFi. It just works over a much larger area than WiFi does. They're more complementary than competitive.