Internet Protocol (IP) telephony can yield big cost savings to both corporations and consumers. It is more efficient than the plain old telephone service (POTS) and is poised to undergo huge growth. Before that growth can occur, however, designers who want to use the technology have to vault hurdles concerning latency, quality, and security. Quality of service (QoS) is the primary problem impeding this growth. A traditional problem with this technology, QoS must improve enough to enable Internet-based services to compete with traditional telephony providers. Many industry pundits think this scenario won’t happen unless IP overcomes these problems . Read the rest of this entry »

The first high-definition-television (HDTV) sets are making their way from dealers’ warehouses to living rooms in several areas of the United States. In another year, the service should be available in more than 30 major cities. With delivery of the first sets and the start of programming, US consumers get their hands on technology that, arguably, is more sophisticated than any ever mass-marketed in this country. Those who have seen HDTV receivers in operation say that, once the units are properly set up, they are easier to use than today’s TVs. Nevertheless, you can make a strong case that the new receivers embody technology that is even more complex than that of high-end PCs. Read the rest of this entry »

The rise of digital technology has changed the way people use and store information. As more and more data takes a digital form—shifting from physical media, such as film, tape, or paper, to bits—the need to protect both the content and the privacy of information has increased. For example, music and video copied from a digital versatile disk (DVD) results in a perfect copy, a factor that has held up the adoption of DVD because studios are afraid to leave their valuable content so vulnerable to theft. Read the rest of this entry »

Global System for Mobile Communications (GSM) phones raise expectations among professional-mobile-radio users to levels that system makers are only now beginning to address. Not long ago, you’d need to be a member of the emergency services or a top executive to make calls from a mobile phone. Now, anyone with $100 to spend can roam most of Europe and enjoy direct access to international communications networks. Consumer models have a lot in common with professional user needs, but there are still compelling reasons why GSM can’t deliver in the professional user market. With dedicated professional-mobile-radio backgrounds, alternative systems compete for private-mobile-radio (PMR) and public-access mobile-radio (PAMR) deployments. Now, professional users can enjoy cellular like telephony and private radio dispatcher services with the same mobile handset. Read the rest of this entry »

There are many ways to bring home a high-speed link beyond the 56-kbps limit that plain-old telephone service (POTS)-based V.90 performance allows. The methods include integrated-services digital network (ISDN), satellite links, cable modems, hybrid fiber-coax, and wireless local loops. But all these methods eventually encounter the virtually universal, metallic local loop that is the “last mile” between the phone company’s central office (CO) and the end user in the public switched-telephone network (PSTN). This loop can be a significant barrier to installing yet another type of path, or it can be a major opportunity—if you can effectively exploit the availability of this enormous, already-in-place link. Read the rest of this entry »

Just a few years ago, the term “network” referred to a mainframe in a back room connected to a series of dumb terminals. Today, the network is a worldwide array of computers connected to increasingly more intelligent clients ranging from personal computers to personal digital assistants (PDAs) to cell phones. Traditionally, these clients connect to the worldwide array over wire or some other physical medium, such as a cable or copper twisted pair. Wired connections provide reliable, high-speed information pipelines, but they tie clients to a location. Read the rest of this entry »

The Bluetooth wireless standard is coming into its own, and hundreds of millions of Bluetooth-enabled products will ship by the end of 2002. The Bluetooth technology will be self-contained within many products; for others, it will be an addition in the form of a PC Card that plugs into a mobile device or a dongle that plugs into a desktop system’s RS-232 or parallel-printer port. As Bluetooth becomes ubiquitous, you’ll find yourself having to test Bluetooth devices at the protocol-stack and RF levels. Read the rest of this entry »

Analog-circuit designs have fundamentally different architectures from those of processor, FPGA, and PLD designs. Once you implement the circuit topology and parameters, the circuit’s signal-processing function is relatively fixed. Sure, some functional blocks exist, such as filters, in which you can digitally adjust cutoff frequency, roll-off, and other factors by varying the clock (for switched-capacitor designs) or adjusting circuit factors via DACs, but these examples are the exceptions. Most designs are fixed in their functions and nearly fixed in their performance. Read the rest of this entry »

If you think that developing new designs for the conventional analog plain-old-telephone-service (POTS) line is like designing for dinosaurs, think again. The Consumer Electronics Association (www.ce.org) estimates that manufacturers last year sold about 16.8 million desktop and laptop PCs, and nearly every one of them had a V.90/56-kbps modem as a standard feature. In addition, vendors shipped millions of relatively invisible embedded modems within devices such as set-top boxes and home-based controllers plus about 5 million retrofit modems for PCs. Read the rest of this entry »

You’ve heard endless predictions about the new millennium, and some of these predictions will even come true. But there’s one low-risk prediction that you can make: Electronic systems will increasingly require point-to-point serial links at the 1-Gbps-and-higher rate between pc boards, chassis, and subsystems. This requirement means that the demands on the physical link will increase, and, if you don’t prepare properly, the physical link will become the slowest and thus the weakest link in your signal-path chain. Read the rest of this entry »