WARREN, N.J. ( ChipWire) -- A company spun off from Lucent New Ventures is using chip-scale integration technology developed at Bell Labs to deliver what it claims is the smallest complete receiver for the global positioning system (GPS) standard to date.
Warren-based SyChip said it has packed the SiRFstarII GPS receiver IC from SiRF Technology of San Jose into an 11 x 14 x 3.5-mm module that includes a 12-channel RF section, baseband and memory. The company's announcement comes just days before Thursday's deadline for cellular carriers to divulge the technologies they will use to meet the Federal Communications Commission's Enhanced 911 (E911) Phase II requirements.
Analysts speculate that carriers will ultimately use a hybrid approach of network- and handset-based technologies to enable cellular systems to provide emergency location data.
The FCC mandate has created a sense of urgency among carriers and handset makers, which initially balked at the prospect of including extra hardware and software in their networks. But with International Data Corp. predicting that the location-based-services market will grow from $554 million in 2001 to $4.9 billion in 2004, suppliers have warmed up to the notion and are rushing to provide fast, accurate, easy-to-use and low-cost locator service schemes.
Three main location-determination methods network-based, handset (GPS)-based or a hybrid of the two are being considered. The SyChip GPS2020 solution plays into the two latter options.
Some handset manufacturers, such as Nokia, are reluctant to use GPS, citing time-to-market issues and the added cost, complexity and footprint of the GPS chip, as well as the need for another antenna.
But "these aren't really issues anymore," said Moses Asom, vice president, chief operating officer and co-founder of SyChip. "Our module simplifies the integration process and comes in at under $75, and we are actively engaged with leading antenna manufacturers to come up with easy-to-implement antenna solutions."
Active and passive antennas are both options, said Asom, and SyChip will work closely with a customer to implement its antenna of choice. Meanwhile, dual-purpose antennas capable of handling both cell-phone and GPS frequencies are eagerly awaited from companies like Rangestar and Terk.
The FCC mandate requires carriers to juggle a range of considerations, such as securing enough compliance among the installed subscriber base to achieve the required 67% penetration. The time-to-implementation and accuracy guidelines in Phase II also affect the choice of a locator approach.
Phase I of the FCC mandate required wireless carriers to deliver to an emergency dispatcher the phone number of the wireless handset originating a 911 call, and the location of the cell site or basestation receiving it. Phase II requires more specific latitude and longitude information, known as automatic location identification (ALI), for the dispatcher.
The FCC has called for 25% of all newly activated handsets to be ALI-capable by Dec. 31, 2001. That rises to 50% by June 2002 and to 100% by Dec. 31 of that year. By then, carriers must be able to locate subscribers to within 125 meters for all 911 calls.
"The only way to ensure coverage for the installed base of cell phone users is to implement a network-based solution," said Jim Moeller, wireless communications analyst with Dain Rauscher Wessels in Boston. "This will help satisfy the FCC requirements initially. However, the hybrid GPS/network solution . . . will be the obvious long-term winner."
Allen Nogee, senior analyst at Cahners In-Stat Group in Scottsdale, Ariz., agreed, citing the indoor-reception problems of GPS and the lack of coverage of network-only solutions. "Without triangulation, accuracy goes way down." In those cases, GPS is the best bet.
Snap Track Inc.'s Hybrid Assisted GPS system is the leading hybrid solution to date. According to SyChip's Asom, it's a prime target along with GPS-only solutions for SyChip's GPS2020 receiver.
The GPS2020 was enabled through Bell Labs' microsystem interconnect technologies (MSIT) chip-scale integration techniques, which SyChip leveraged when it was spun off. MSIT integrates passive devices within a high-Q silicon substrate and combines that with flip-chip and chip-on-chip schemes.
Though it has long been notoriously difficult to achieve embedded passives at acceptable levels of quality and accuracy, SyChip's figures show tolerances of 1-to-3% for inductors and 1-to-5% for resistors and capacitors. Q factors are said to be between 70 and 80 for inductors and up to 100 for capacitors.
Integrating the RF components on the substrate slashes the overall board space required. The next step was to integrate the SiRFstarII GPS architecture.
Asom said the high integration enabled by the interconnect and packaging scheme has mitigated parasitics and improved performance by shortening traces and memory distances.
The SiRFstarII architecture builds on the SiRFstarI core, adding an acquisition accelerator, differential GPS processor, multipath mitigation hardware and satellite-tracking engine. Based on a 50-MHz ARM7 CPU, SiRF calls it the first GPS architecture designed to be available both as an integrated chip set or as an intellectual-property core.
The GPS2020 comes with the RF IC, baseband processor and 8 Mbits of flash memory. The RF end includes a low-noise amplifier, surface acoustic wave filter, phase-locked loop, image-rejection mixer, automatic gain control amplifier, and A/D converter. RF image suppression exceeds 20 dB. The on-chip 1,565.97-MHz PLL serves as a local oscillator source. A 24.55-MHz clock is used as a reference, and the PLL's loop filter is set to around 400 kHz.
The automatic gain control register contains a 5-bit word, allowing more than a 50-dB IF gain adjustment range in approximately 1.7-dB steps. The output of the AGC drives the A/D converter.
Along with the ARM7, the baseband includes a DSP engine, 128 kbits of ROM and 2 kbits of SRAM. The output data can be sent to one of several available serial ports, with SyChip-customized formats to the host processor.
Of the available 8 Mbits of flash memory integrated on the GPS2020, 4 Mbits are used for the GPS system; the remaining 4 Mbits are available for user applications.
One key feature, especially in the context of handset operation, is TricklePower, which cycles the power to the RF chip set periodically so that it operates only a fraction of the time. For the CPU, the DSP can be turned off when not tracking.
The device comes with a full complement of application programming interfaces to match customer protocol software and ease system integration. A complete reference design for active and passive antenna solutions for specific customer applications is provided, as is RF system analysis, to prevent phone interference.
The device comes in a ball-grid array package and is set for release by May. A full-function evaluation kit will be available for $1,000 starting Dec. 15.