Packetized voice comes to in-building wireless phones
By Loring Wirbel, EE Times
May 29, 2001 (4:57 PM)
URL: eetimes.com
BOULDER, Colo. — The unlicensed in-building phones developed for the retail warehousing and health care industries may end up beating standard cellular telephony to voice-over Internet Protocol packet service. SpectraLink Corp., a pioneer for the last decade in 900-MHz and 2.5-GHz unlicensed in-building phones, launched the NetLink IP Wireless Telephone recently as a low-cost alternative to voice calls.
Packet-data service over the 2.5-GHz band may be a natural eventual fringe benefit for shifting to IP phones, said director of marketing Ben Guderian, but data was not a driving force in developing the phone. Instead, SpectraLink wanted to interface to the emerging IP-based PBX and keying systems in the corporate market. The company consequently developed a handset supporting Cisco Systems Inc.'s Skinny Client Control Protocol.
At the same time, the phones can interoperate with 802.11b wireless local-area network (LAN) access points. Such access points from the Cisco Aironet group incorporate a SpectraLink Voice Priority algorithm to ensure low-jitter, low-latency voice across an 802.11b infrastructure. The handsets also are compatible with the Lucent Orinoco, Intermec MobileLAN and Enterasys RoamAbout access points. For client IP protocols, the handsets currently support H.323, and gateway protocols such as Megaco will be added in the future.
SpectraLink uses the same ruggedized case for the 6-ounce phone that is used in its standard NetLink models. Neither the circuit boards nor the subsystems assembly is outsourced to any great extent, since SpectraLink traditionally has tried to keep tight controls on manufacturing quality. Phones are designed to survive 20-foot drops and similar rough treatment, since they are used in factory floor and warehouse stocking applications where common cellular handsets would not survive.
Mark Angliss, manager of quality and process engineering at SpectraLink, demonstrated several tests for stressing the in-system diagnostics package inside the handset. In many cases, dedicated test equipment for the handsets must be developed at SpectraLink, both because the unlicensed industry has no equivalent to Global System for Mobile Communications Type Approval tests, and because SpectraLink requires ruggedization beyond ISO 9002 manufacturing requirements, for which no equipment exists.
SpectraLink will roll out several telephone, access-point and gateway bundled packages late in the year, as interoperability with other vendors' systems is shown. Individual handsets will be priced at $679 and will begin
shipping to customers in the third quarter. |
