Thanks for a very good overview of the infrastructure and network performance differences of GPRS versus WCDMA.
Your summary does however beg the question: Can GPRS operators afford to displace billions of minutes of voice airtime to relatively low revenue generating packet traffic?
One answer is that since GPRS IP traffic takes a back seat to voice, meaning that the network grants priority to voice traffic, this is not really an issue.
When a voice request for service is made, and all GSM timeslots are used, a few GPRS users will be released from the network in favor of that additional voice user. So IP is not hogging up capacity, it is using up excess Erlangs that would have gone unused anyway. But at the same time, operators cannot guarantee that the desired Quality of Service will be achieved consistently.
I believe this is one of the bone of contention that the HDR and CDMA2000 folks have over shared voice and IP spectrums in general and over GPRS and WCDMA in particular.
From the standpoint of the user then, the problem with GPRS is not so much the lack of high speed throughput but rather the fact that QoS cannot be guaranteed. So while business folk are waiting for their train or plane and attempt to access their email during the system busy hour, they will likely get denied service. Corporate customers are likely to demand a consistent level of service and be willing to pay a premium for it as well. But if 10 years of GSM is any indication, operators are very reluctant to offer segmented service levels for different users, as it would be undemocratic and could hurt their corporate image if it came to be known that this form of wireless segregation was going on. Ericsson, for example, has in its software the option of granting priority to certain “gold” customers, but to the best of my knowledge, this special feature (“Efficient Priority Handling”) is used very very sparingly. And certainly not in european markets.
So GPRS operators will either have to get used to the idea of offering subscribers “what they pay for” and thereby guaranteeing somehow QoS or risk losing business customers altogether.
The alternative is to use GPRS as a data platform to enter low bandwidth mass consumer data markets. Bundled with intelligent network features, such as location based information, GPRS need not require a higher throughput than 14.4kb/s to offer a cheap and commercially viable step up from Wap. With the current state of handset technology, this backdoor approach to GPRS may in fact prove more beneficial to all parties. GPRS would create a latent demand and awareness of data services in the consumer; that would benefit WCDMA and CDMA2000 alike.
rf_hombre |
