All you really get with dv is the mixing of data+voice - against Viterbi's very good judgement...
Ben,
If it's not too much trouble, would you please provide a link to Viterbi's expression of that opinion?
I share his opinion. With all the CDMA2000 spectrum (in any one geographical area) devoted to 1xEV-DV, the system can adapt to current demands, 100% voice, or 100% data, or any voice/data combo in between. But is this what carriers want? In particular, would they want 100% of the capacity used for voice?
An analogy: When installing a phone system for a company, one can install incoming trunks (for network originated calls only), outgoing trunks (for office originated calls only), two-way trunks (either end originates), or any combination of the three. If 100% of the trunks are two-way, the majority may become used as outgoing trunks, drastically reducing the QoS for incoming calls, e.g., from customers. Not good!
A similar situation exists for 100% 1xEV-DV ("DV"), only here the balance is between voice and data traffic.
2.5 MHz of spectrum can be allocated: 50% 1x (not 1xEV-DV), and 50% 1xEV-DO ("DO"). Guaranteeing 50% for voice comes at a price. Voice cannot use *more* than 50%. Ditto for data. (I may have a logic error here, since I don't yet understand the orthogonality of DO. I stated 'not DV' since 100% of capacity could then again be data.)
With 3.75 MHz spectrum to allocate, one can choose 33% 1x, 33% DV, and 33% DO. (I'm thinking that this can be done with a couple extra cards in the BTS, at most.) Hopefully, one would be able to direct overflow traffic from both 1x and DO, to DV spectrum. This type of traffic management would permit between 0% and 66% of total capacity for voice, and between 0% and 66% for data, depending upon demand. Definitely better imho than 0-50%, but that extra 16% is probably not worth the trouble and cost.
While writing this post, however, I realized that Qualcomm (and the standards bodies) need to include within DV specifications, the capability to configure the maximum percentage of capacity that may utilized for both voice and data. Note, the sum of the two percentages would exceed 100% in any sanely configured DV network.
With the capability above, one just makes all available spectrum DV.
Thanks for all your posting of news.
Ron |
