AT&T Wireless Services has unveiled personal Air Communications Technology, a new open standards-based architecture for two-way messaging that the company expects will become an industry standard for narrowband personal communications services.
Armed with pACT, AT&T is first to challenge Motorola Inc.’s FLEX technology in the two-way paging arena. Dueling for customers, AT&T believes it has Motorola beat on the scores of capacity, data security and location services.
Ken Arneson, vice president of business development for AT&T Wireless Services’ Messaging Division, said AT&T recognized three elements for successful narrowband PCS: providing a device that is small, conserves power and is inexpensive. As such, pACT is rooted in Cellular Digital Packet Data technology, an Internet Protocol general purpose wireless data protocol. IP allows for easy integration with other networks, service centers and equipment, said AT&T. CDPD is maximized with pACT for small size, said Arneson. AT&T has taken the richness of CDPD and eliminated unnecessary features like channel-hopping, Arneson added.
Further, CDPD brings data security to two-way messaging like it does on cellular networks. “Authentication and encryption follow to the NPCS environment,” said Arneson. The technology “provides a great environment to receive messages without fear they’re intercepted or cloned.” People communicating by e-mail or making stock trades on their pager device want that assurance, he said.
The nature of pACT architecture, whereby paging devices can be located by the network anywhere in the nation, makes it a good fit with tracking and dispatch-oriented applications, said Arneson.
AT&T said devices including two-way pagers, personal digital assistants, home monitoring devices, telephony applications and Personal Computer Memory Card International Association (PCMCIA) cards will operate using pACT architecture.
Not only does pACT operate using open standards, hardware and software developers can design pACT-based subscriber units without paying licensing fees, said Arneson.
L.M. Ericsson’s mobile data division is involved with pACT, but their specific relationship with AT&T has not been announced. Arneson said the company plans to make its own announcements in the near future and conceded AT&T’s relationship in terms of pACT has been “vastly overblown in the press.”
Ericsson officials wouldn’t comment on their role in the technology.
NEC Corp. supports pACT and will be making related announcements, as well, Arneson noted.
A number of narrowband PCS service providers are evaluating pACT. Among them the companies delete 9the companies9 are MobileComm-the Miss.-based BellSouth paging subsidiary to be acquired by MobileMedia Communications Inc. of New Jersey-Benbow PCS Ventures of California and Bell Mobility of Canada. Lanser Technologies of Canada, of which AT&T is a minority owner, has committed to nationwide deployment of pACT.
The pACT architecture is symmetrical. Inbound and outbound data rates are equal in capacity, and therefore speed, which optimizes spectrum use and allows greater flexibility for various messaging functions, Arneson explained.
E-mail is a symmetrical application, as it allows reciprocal messaging. Acknowledgement paging is an asymmetrical application that allows longer incoming messages on a high-speed forward channel, but limits users to brief responses on the slower return channel. Both symmetrical and asymmetrical applications can run with pACT architecture, said Arneson.
Messages using pACT travel at 8,000 bits per second inbound and outbound. Motorola’s ReFLEX 25, ReFLEX 50 and InFLEXion two-way protocols are asymmetrical with inbound and outbound speeds of 9,600 bps and 6,400 bps, 9,600 bps and 25,600 bps and 9,600 bps and 112,000 bps, respectively.
But numbers aside, Arneson emphasized how much network capacity and the method of message transmission affect the speed messages will travel. The smaller a zone of transmission-be it two states with multiple base stations or one lone base station-the fewer people covered within that zone, and the greater the capacity.
Keeping this in mind, a pACT-based network will provide the necessary capacity and be more efficient than other networks, said AT&T. Here’s why: A network using pACT will be configured like a cellular network, comprised of intelligent base stations that are equipped with transmitters and receivers to route messages.
“Moving from one cell area to another there is a handoff just like with cellular,” said Arneson. The network recognizes a pACT-based messaging device so the device can be contacted directly by the nearest transmitter. This network is active, where a ReFLEX network is passive, said Arneson.
“In a 6,400 [bps] environment messages are paging-like,” he said. These networks will send paging signals to a zone the user has specified as his home area. If not answered in that zone, the paging signal is broadcast repeatedly over a larger area, sometimes nationwide. This consumes spectrum capacity. As a ReFLEX system takes on more subscribers, capacity also could become limited, said Arneson.
The pACT technology “will support millions of customers in a heartbeat, without breaking a sweat,” asserted Arneson. One zone can be a single base station on a pACT network, said Arneson, rather than a geographical area comprised of multiple transmitters. “If we need more spectrum, we’ll add more base stations.”
Motorola said ReFLEX will not have a capacity problem. The number of transmitters can be adjusted like cellular, to address the number of subscribers, said Larry Conley, corporate vice president and director of worldwide markets for Motorola’s Advanced Messaging Systems Division. Thus far, Motorola has signed on Mobile Telecommunciation Technologies Corp., first to market with the SkyTel 2 Way network. PageMart Inc. and Paging Network Inc. plan using InFLEXion technology for their voice networks. PCS Development Corp. of Greenville, S.C., plans deploying an InFLEXion-based voice network. MobileComm, Insta-Check Systems Inc. of Miami, Ameritech Corp. and AirTouch Communications Inc., are testing and evaluating the FLEX technologies, added Conley.
An automatic registration network feature adds to efficiency as well, eliminating the need to retransmit messages to ensure a customer has received them.
Initially AT&T had considered developing a voice product for narrowband PCS, but decided against it.
“The research says nonreal-time voice is a winner, but we don’t think its right for narrowband PCS,” Arneson explained. AT&T is considering offering nonreal-time voice services over its cellular networks, a more efficient alternative, said Arneson, since the company would be using existing infrastructure and gain time-to-market advantage over narrowband PCS.
