Communications systems operators face at least one continuing reality: their customers want ever-improving services even as networks become overloaded with subscribers. Additional subscribers on a wired or wireless communications network benefit the business side of the operation. But as more subscribers are added to a network, its capacity is pushed to its limits, requiring the assistance of advanced technologies, in the form of hardware and software, to increase the capacity without degrading performance. A great many device, component, system, and software developers are contributing to improved communications technologies even as the demands for service skyrocket.

On the device side, Altera Corp. (www.altera.com) recently announced a 10-Gb Ethernet (10GbE) reference design that targets designers using the XAUI communications protocol. The reference design, which successfully passed University of New Hampshire Interoperability Lab (UNH-IOL) 10GbE validation tests, leverages the firm’s high-performance Arria and Stratix families of field-programmable gate arrays (FPGAs) for reliable connections to 10GbE backplanes and networks. The reference design, which can be used for developing line cards and system controllers within network routers, Ethernet switches, and storage systems, is compliant with the IEEE 802.3ae communications standard. It consists of an encrypted design library, detailed 10GbE application note, simulation test bench with test cases, and user configuration graphical-user-interface (GUI) software. The reference design allows designers to quickly implement a wide range of the company’s FPGAs into a multi-10GbE system.

Jeff Lapak, the 10GbE Ethernet Consortium manager for UNHIOL, remarked: “Performing testing at the UNH-IOL helps to ensure interoperability with other 10GbE devices and equipment. We worked closely with Altera to test the Stratix II GX FPGAs and their conformance to the standard as well as their interoperability with existing 10-Gb/s Ethernet devices.” In addition to being compliant to the IEEE 802.3ae 10GbE standard, Stratix II GX FPGAs successfully passed all the pertinent UNH 10GbE hardware tests, including Clauses 4 (MAC), 31 (Flow Control), 46 (RS), 47 (XAUI), 48 (10GBASE-X PCS), Clause 54 (CX4), XAUI interoperability tests, and optical module interoperability tests with various optical X2 modules. The reference design was verified in simulation and hardware tested in Altera’s PCI Express Development Kit, Stratix II GX Edition with industrystandard 10GbE test equipment and CX4 and X2 adapters.

On the component side, Vectron International (www.vectron.com), a leading supplier of frequency control and timing products, recently introduced its VSS4 oscillator for spread-spectrum applications in which electromagnetic interference (EMI) must be tightly controlled. The VSS4 oscillator, developed for consumer, commercial, and enterprise applications, maintains EMI levels within US Federal Communications Commission (FCC) Part 15 requirements. Through the use of spreadspectrum techniques, energy is distributed across a fairly wide spectrum (compared to conventional clock oscillators) but at low average levels in order to comply with the FCC regulations.

According to Alan Mond, vice-president of Global Sales for Vectron, “Vectron is committed to growing our industry-leading precision oscillator portfolio to meet our customers’ changing needs. This dedication to continual product innovation is particularly important to customers in the communications and consumer electronics markets, who are looking to evolve their platforms while meeting stringent industry regulations. The VSS4 spread-spectrum oscillator provides these customers with the stability and performance they have come to expect from Vectron, while enabling them to comply with FCC restrictions.” The VSS4 oscillator can be specified from 12 to 168 MHz. It is supplied in a ceramic package measuring 5.0 x 3.2 mm and operates from a +3.3-VDC supply. It has an enable/ disable feature to allow the clock output to be disabled for board testing.

Earlier in the year, the firm announced a clock oscillator based on microelectromechanical- systems (MEMS) technology for high-shock, high-vibration applications. Qualification testing of a 125-MHz oscillator showed no degradation in performance to 30,000g's force in each axis. The clock is available in a 5 x 3.2 mm AFN package at frequencies from 1 to 130 MHz.

Higher up the “design chain,” spreadspectrum- radio innovator FreeWave Technologies (www.freewave.com), and wireless communications carrier Arcadian Networks (www.arcadiannetworks.com) recently announced that they had developed a 700-MHz radio solution for the energy industry (see figure), just six months after the two companies announced a joint strategic partnership. The new radio solution allows oil and gas companies as well as electric utilities (in the US only) to take advantage of advanced Industrial- Scientific-Medical (ISM) technology in a private, licensed, 700-MHz radio system. Arcadian Networks and Free- Wave will each market, sell, and distribute the 700-MHz radios.

The radios operate in the licensed industrial band at frequencies from 757 to 758 MHz and 787 to 788 MHz. They offer a 30-mile range with clear line of sight and data throughput of 19.2 kb/s using two-level Gaussian frequencyshift- keying (GFSK) modulation and 38.4 kb/s using four-level GFSK. The radios provide error-free communications thanks to a 32-b cyclic-redundancycheck (CRC) algorithm with automatic retransmission. They can be equipped with a variety of interfaces, including RS-422 and RS-232 ports.

Jake Rasweiller, vice-president of engineering and network operations at Arcadian Networks, noted: “The FreeWave radios enhance Arcadian Networks’ custom, private, wireless services, with new voice and data capabilities. Providing our customers with diversity of choice, scalable performance, and flexible price-points is an essential element of our service in building out the nation’s only mission-critical network devoted to electric utilities and oil and gas companies. FreeWave’s 700-MHz wireless radio is a great proof point of this philosophy.” FreeWave Technologies spokesperson, Colin Lippincott, added: “The 700-MHz band offers a great solution to those looking for a choice. Now, oil and gas and utility companies can realize the combined benefits of having a private, secure network with the most advanced, reliable and robust radio communications technology of its kind. It opens up applications and opportunities for the companies that want a licensed network and don’t want to use or cannot use other licensed options.” The boardlevel 700-MHz radios function without need of additional shielding across a wide supply range (+6 to +30 VDC) and can handle operating temperatures from -30 to +70°C.

As part of the ever-expanding cellular landscape, market research firm ABI Research (www.abiresearch.com) foresees that smaller cell sites, such as picocells and femtocells, will be a larger part of the initial third-generation (3G) Long Term Evolution (LTE) cellular network architecture. These smaller cell sites, although their designs have come after the development of earlier cellular networks, have been available for some years preceding the build out of LTE networks. According to ABI senior analyst Nadine Manjaro, “In most parts of the world, LTE will be deployed using higher-frequency bands. Higher frequencies penetrate structures less effectively than low frequencies, so femtocells and picocells offer an attractive way to compensate for lower indoor signal strength and provide LTE’s touted bandwidth. Our forecasts show an upswing in femtocell and picocell penetration that coincides with the expected LTE deployment timeframe.”

Projections are collected in a market study simply titled, “Long Term Evolution (LTE).” The study also charts the LTE timeline, strategies of different operators, and migration plans from earlier cellular technologies. In Europe and other regions, LTE will operate in the 2.6-GHz band, while in the US it will largely be found in 700-MHz range. In China, TD-LTE will be most likely be deployed in bands of 1880 to 1920 MHz and 2010 to 2025 MHz, so the need for femtocells may be considered less pressing in those areas.

ABI also predicts the market for Universal Edge Quadrature Amplitude Modulation (QAM) equipment will grow rapidly in 2009. In a research brief entitled “Universal EdgeQAMs,” the firm notes that strong growth is expected to continue through 2013 to a market size of about 1.5 million communications channels. These universal designs, which reside on the edge of a fiber-optic network, service individual households by transporting network information by means of RF signals.

As ABI Research Principal Analyst Robert Clark offers, “Cable operators faced with growing competition from Internet protocol television (IPTV) seek inexpensive ways to increase bandwidth. While QAMs are more cost-effective than other ways of doing this, many operators have decided to focus in the short term on reclaiming bandwidth by riding on the coattails of the analog-todigital TV switchover. After that transition, operators will move to edgeQAMs as a next step.” The first wave of QAM deployment is likely to occur in markets where competition from IPTV is particularly strong, countries such as South Korea, Japan, and France.

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