Replies to post #14683 on Qualcomm Inc (QCOM)

[slacker711]

HSDPA vs. DOrA

As I’ve stated before (no doubt obvious to most), I’m no technologist. And, perhaps I’m way off base and missing something here, but it appears that Rysavy’s own data proves my point (appears to distort EV-DO RevA performance) -

+ Table 1 (Comparison of Capabilities of Technologies)

 
 Average User Throughputs for File Downloads  
  
 UMTS- HSDPA  550- 1100 kbps 
 EV-DO        400-700 
 EV-DO Rev A  Slightly improved over EV-DO  
 

+ Figure 14 (Comparison of Downlink Spectral Efficiency)

Table 1 reflects EV-DO between 72% to 64% as efficient as HSDPA (and EV-DO RevA (slightly improved over EV-DO). Yet Figure 14 depicts the Downlink Spectral Efficiency (bps/Hz/section) for all three Wireless Technologies roughly the same-

 
 HSDPA         0.63 
 EV-DO         0.60   95% as efficient as HSDPA 
 EV-DO Rev A   0.62   98% as efficient as HSDPA

I hate to use Eric's words, but you really are mixing apples and oranges.

Forget all of the technology jargon. Look at it from a customer point of view. If you buy a HSDPA laptop card, you can expect download speeds between 550Kbp and 1100Kbps. If you buy a current DO laptop card you can expect speeds between 400 and 700Kbps. The consumer is going to get a faster experience with HSDPA than with current DO cards (and likely DOrA cards as well).

The second half of the customer experience is pricing. That is where the second table comes in. If the three technologies are equivalent, they will cost about the same to provide a given number of megabytes.

So, a HSDPA modem could provide the same number of bytes at a faster speed for the same price as DO. I really dont think that this is a controversial claim. It is simply the nature of the 5MHz bandwidth that HSDPA is going to use.

Note, that I'm not endorsing the exact numbers that Rysavy provides....but they are consistent.

Slacker

[jackmore]

Jim and Slacker,

From my perspective the "distortion" in the tables has little to do with the downlink speed comparisons. It's what's not displayed that makes it a little slight of hand. What's not there is uplink speeds. The guild is happy to compare HSDPA with DOrA on the downlink (and fudge some). Not so anxious to compare on the uplink. Why? We all know it's because they still need HSUPA to solve that piece. DOrA will do that for CDMA operators, and it seems likely, at this point, that it will reach market first.

p.s. Yes, I know, the paper was on HSDPA, so they could rightly claim that it wasn't supposed to address uplink.