Powering The Information Age

Wireless has become a ubiquitous term in recent years. The definition of wireless technology is the communication of information without the use of some sort of conduit. The original conduit of course was a wire made out of some sort of metal; however, in more recent years other conduits have emerged such as fiber. Removing the conduit, the most common transfer medium is electromagnetic radiation which includes a whole spectrum including light, radio, and other types of waves. Depending on the frequency, they can travel long distances at speeds up to the speed of light.

Electromagnetic radiation is not a new discovery. In 1865 James Clerk Maxwell, a Scottish physicist published a set of equations hypothesizing the existence of electromagnetic radiation. By 1889 a German physicist, Heinrich Hertz produced the first observable electromagnetic waves. With the discovery of how to produce electromagnetic waves, a whole host of discoveries followed.

First was the Wireless Telegraph. Since the introduction of the wired telegraph in 1837, it had emerged as a way to communicate over long distances almost instantaneously. The discovery of how to produce electromagnetic waves quickly removed the need for laying down wire from point to point and introduced a flexibility to the technology. Since those early days, the technology has evolved and advanced.

First there was radio, eventually followed by television. The introduction of the transistor in the 1950's and the eventual emergence of the semiconductor industry enabled the miniaturization of circuits to build smaller devices making access to information portable. At first, it was the transistor radio and today, there are few people who do not have a cellular phone.

It is not only communications that benefited, the ability to provide information just as needed has led to tremendous advances in our daily lives. Driving last night to pick up my daughter and son-in-law at the airport, I relied on a navigation app to provide me with alternate routes to the airport since construction was ongoing. The use and publication of information has propelled the world foward.

Access to information has always advanced society. Although there are differing opinions, the invention of the printing press in 1436 definitely had an impact on Europe and contributed to the emergence of the Renaissance. The ability to gather information that was not controlled by the government changed the face of nations. The opposition to the Vietnam war among the broader US population can be directly linked to news reports from Walter Cronkite and Morley Safer. Twenty-four hour news stations, have made it so the governments are no longer the first to get information. And of course the internet and social media have had a major impact on our society.

It wasn't until the 21st century that access to information has become ubiquitous. The first phones with internet access came out in 2001 and since the introduction of the iPhone in 2007, using the internet as a backbone, applications providing access to all sorts of information is today at everyone's fingertips anytime anywhere. Of course, to deliver that information we have seen the development of wireless technologies. For smart phones we have seen the technology go from 3G to 5G offering more data and faster speeds.

The transmission sites for this information comes in many forms; cells, small cells, point to point and point to multi-point radios, wireless networks, local area networks, and wide area networks just to name a few. Frequently these transmission points are not conveniently located where power is available. Thus to power these devices it has been popular to rely on Power over Ethernet (PoE).

PoE is the ability to deliver both data and power over an ethernet cable. By adding power to an ethernet cable that already contains data, wireless devices can receive information for transmission and the power required to transmit the information. PowerDsine first introduced the PoE Power Source Equipment (PSE) IC in 1997. This semiconductor was capable of adding power onto an ethernet cable and is commonly found in such devices as switches, routers, gateways, and midspans. PowerDsine also was the first to introduce the PoE Powered Device (PD) IC capable of taking power off of the ethernet cable and using it to power the end device such as a wireless access point; one of the most common devices powered by PoE.

Since switch manufacturers in 1997 had not yet designed this technology into their switches, in 1998 PowerDsine introduced the first midspan, also known as the injector. This is a device that contains a PSE IC that that takes input from ethernet cable containing data from the switch, adds power onto the line, and outputs an ethernet cable that can deliver both power and data over 100 meters.

Today there are many different types of midspans or injectors. PowerDsine, which today is known as the Microchip Power over Ethernet Business Unit, produces single and multi-port midspans with data rates ranging from 1 Gbps to 10 Gbps. Microchip also makes midspans for a wide range of environments including indoor, outdoor and industrial. Microchip even has an outdoor PoE Switch that can upload data from several kilometers using a fiber optic link, and then provide power and data in up to 4 PoE devices.

Back in 1998 there were no ethernet switches providing PoE power, however, PoE Switches are available today. So why would anyone need a midspan in today's environment?

Only 20% of existing network infrastructure has the ability to provide power. Thus if installing a wireless device requiring PoE power, the easiest way to provide that power is through the use of midspan or injector. And today, only 50% of switches being sold today provide power. Thus there is no guarantee that a new switch will be able to power a device.

Finally, even when a switch does provide power, it has a limitation called a power budget. This is the total amount of power that the switch has to distribute over the ports. Frequently, switches do not have enough of a power budget to provide full power over every port. Therefore, to supplement the ports that cannot provide power, a midspan is still needed.

Midspans are the perfect solution to provide wireless transmission points the power required along with the data to fuel the growth and distribution of information. Today we continue to see PoE technology adoption and expansion. An example of this is the use of PoE by Wireless Internet Service Providers (WISPs). If you would like to see an example PoE in use, read the Sail Internet Case Study.

https://ww1.microchip.com/downloads/aemDocuments/documents/POE/ProductDocuments/SupportingCollateral/00004836A.pdf

Microchip is proud to be participating in this year's WISPAPALOOZA October 9th - 12th in the Paris Hotel in Las Vegas. If you would like to learn more about PoE, or the many options Microchip can provide, please stop by our booth.