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When seconds count: PTT players address latency issues

While many industry observers applauded Verizon Wireless’ introduction of its Push to Talk service as a way for the carrier to attract high-end business customers interested in a walkie-talkie services, some were disappointed with certain latency issues in Verizon Wireless’ CDMA-based service that failed to match some benchmarks set by iDEN networks.

Those issues included call set-up times, which in some instances were in excess of 10 seconds, and intra-call latency of between one and four seconds compared with sub-one-second times recorded using Nextel Communications Inc.’s Direct Connect offering.

Analysts noted that while some of these issues will be addressed as the CDMA technology matures, enhancements are not expected in the near future.

“While we recognize that over time we would expect to see improvements in performance through further iterations of the CDMA technology, we are not aware of any near-term technology enhancement that will improve existing performance,” said Legg Mason in a report.

Legg Mason added that until such enhancements are made available, additional CDMA-based walkie-talkie deployments could be delayed.

“In our opinion, considering that many of the CDMA carriers are using the same vendors, the market performance of the Verizon PTT product may further stall or shelf pending PTT rollouts from Sprint PCS and Alltel,” Legg Mason’s report noted.

Verizon Wireless did not comment on latency issues with its Push to Talk service, and infrastructure provider Winphoria Networks, which is a subsidiary of iDEN developer Motorola Inc., said it did not want to comment due to current legal proceedings between Verizon Wireless and Nextel.

Sprint PCS said it plans to launch its ReadyLink-dubbed push-to-talk service by the end of this year, and it expects the service to compare favorably against current offerings.

“Tests are going well,” said Sprint PCS spokesman Dan Wilinsky. “We are going to get it right from the start, and we are confident we are going to launch with a competitive product.”

Wilinsky added that Sprint PCS expects its PTT service will take market share in both the business and consumer markets.

While consumer reaction to increased latency in PTT services remains mixed, a number of sources expect the CDMA industry to quickly introduce improvements to the technology designed to improve data networks for what essentially are Voice-over Internet-Protocol-based services.

CDMA carriers are expected to solve the latency issue in part through network enhancements, which includes deploying higher-speed and data-only CDMA2000 1x EV-DO technology.

Nortel Networks Ltd., which signed a $1 billion infrastructure contract with Verizon Wireless last week that includes the deployment of EV-DO infrastructure, noted that while latency is a function of how the CDMA technology has been specified to work and how operators have set up their networks, there are enhancements that can be made to the networks to improve data performance.

“There are capabilities in the technology that will provide for the ability to make improvements,” explained Steve Searles, vice president of CDMA marketing for Nortel. “1x shares data and voice in the same channel, while DO is data only and in addition to providing a higher bandwidth, it provides a dedicated channel for data that does not have to compete with or support a voice channel.”

Searles added that while there will be enhancements available for CDMA networks, carriers ultimately must decide how to implement those options.

“It’s one thing to talk about what a technology is capable of and another on how a carrier will take advantage of it,” Searles said.

While some expect enhancements to the technology will improve performance, others note that latency issues need to be addressed on the hardware side of networks.

Sonim Technologies, which is developing an embedded PTT solution with infrastructure provider L.M. Ericsson, said its testing has found latency bottlenecks caused by network equipment.

“We have found that most latency issues are at the base-station level,” said Wade Vesey, chief marketing officer at Sonim Technologies, adding that one of the reasons the company was working with Ericsson on its standards-based solution was because Ericsson had a strong infrastructure presence with most network operators.

CDMA carriers also could see some benefit in the future as analysts expect Nextel to migrate to a CDMA-based platform eventually, though it is not expected to make that move until a CDMA-based walkie-talkie service can match the current performance of its iDEN network.

Nextel has begun to highlight the latency issues between its iDEN-based service and Verizon Wireless’ CDMA-based service through a number of high-profile advertisements asking “What part of `instant’ don’t the other guys understand?” In the ads, Nextel touts its sub-one second call set-up and latency as well as its more than 11 years of experience in offering push-to-talk services and more than 12 million customers with access to the service.

For their part, GSM-based carriers are also expected to see latency improvements with enhancements to their networks.

“Our service might be a little quicker on an EDGE network,” said Harry Eschel, founder and executive vice president of Fastmobile Inc., which began offering a multi-messaging platform that included a walkie-talkie-type service for GSM carriers earlier this year.

Regardless of the possible technology enhancements, some admit both CDMA- and GSM-based networks could still fall short of the “Nextel standard” simply due to the bottom line.

“Nextel has almost $1 billion invested in its network and it works at a $1 billion level. Other carriers are not interested in that level of capital expenditures for their networks and that could lead to a difference in performance,” said Sonim Technologies’ Vesey.

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