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Mikael Bäck, head of WCDMA radio networks at Ericsson, points out that every dropped call costs money and that the long-term cost of inferior network performance can be substantial. "An operator suffering from poor reliability faces many headaches, such as lost revenues, lost customers and lowered customer loyalty," Bäck says. "Customer retention activities such as handset subsidies are among the single biggest costs for most operators, and buying back a lost customer can cost a fortune."

However, some operators demonstrate an in-service performance of their WCDMA networks that consistently beats the competition. German telecom monthly Connect recently tested the country's four 3G operators on three key performance indicators – packet-switched service reliability, amount of dropped calls and average call-completion time. The results showed that Vodafone and E-Plus, both of which operate networks supplied by Ericsson, rated consistently better in all three areas.

Ericsson also undertakes its own measurement of the in-service performance of its networks, and Bäck says: "Our WCDMA networks have higher reliability than any other vendor on the market, and their performance is getting very close to that of GSM."

Figures from an Ericsson study done in November 2004, based on a world average from the 3G networks in commercial operation that are supplied by Ericsson, show a reliability rate for WCDMA of 98.2 percent, compared to the 98.8 percent delivered by its GSM networks. Ericsson's own studies also measure performance indicators such as speech-call set-up time and call set-up time between mobile phones. "We are ahead of the competition in these areas, too," Bäck confirms.

These reliability rates are unheard of in the traditional IT industry, where many vendors are trying to ride the all-IP bandwagon and break into the telecom sector. Bäck points out that their solutions remain a far cry from telecom grade in terms of quality. "Ericsson's WCDMA can meet any wireless broadband technology system, and offer the same range of interactive services with better spectrum efficiency, in-service performance and reliability – at the same cost," says Bäck.

One reason for the high reliability of Ericsson WCDMA is its interoperability with GSM networks, which results in smooth handovers and prevents dropped calls. Bäck explains: "Because we're the biggest in both GSM and WCDMA, nobody is better equipped to ensure inter-system handover of packet-switched and voice services. We also offer operators a common operations and support system (OSS) for both technologies."

Bäck says the bulk of Ericsson's research and development efforts in developing new networks have focused on three areas – to develop and facilitate supreme mobility, optimizing load management and managing handover within WCDMA as well as between WCDMA and GSM.

In general, poor network reliability can be caused by many factors. In the early days of UMTS rollout, poorly functioning 3G handsets were to blame for at least half the dropped calls. On the network side, having an insufficient number of base stations may lead to inadequate coverage, which the end user experiences as low reliability.

Ericsson is always testing the interoperability of new handset models before they reach the market, ensuring sure they work with the company's networks. What can an operator do to enhance reliability? According to Bäck, "Ericsson offers a wide range of services in radio network tuning. Our experienced staff are able to set all the right parameters and lower the dropped-call rate in the process."

Unlike in GSM, cell size affects capacity in WCDMA. As a result, the tilting of base station antennas has become a task best undertaken by experienced technicians. Network planning in WCDMA also requires a different approach from GSM, since it is based on an access technology that produces a clear trade-off between capacity and coverage (cell size). A third difference to GSM is that WCDMA systems contain much more software, which obviously paves the way for a larger amount of coding errors from, in particular, vendors who have only recently implemented WCDMA. "After seven years of system development, we're practically bug-free," Bäck says.

He points to other research-based features that make Ericsson WCDMA more reliable than competitor's. "Unlike most of our competitors, we offer channel rate switching, which is important to prevent dropped calls, especially for data services."

This feature automatically lets the network continuously increase or decrease the bit rate, depending on a service's radio requirements as well as on the number of other active subscribers. Each user gets exactly the bandwidth there is power available for, given the demands from other active users.

Other unique features that make Ericsson's WCDMA more reliable are advanced algorithms for admission and congestion control.

Read more about Ericsson's GSM and WCDMA solutions.