Tag Archive for IEEE

| July 12, 2012
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Power Over Ethernet 802.3at

Power Over Ethernet 802.3atA client recently asked what happened to the network design rule of thumb which said do not install data cables anywhere near electrical cables? The fear of cross-talk, interference, and corruption of the data traffic seems to have disappeared with power over Ethernet. He rightly pointed out that now it seems OK to mix data and power in the same cable going to a networked device. Power over Ethernet (PoE) is similar in principle to the way that the copper wire pair that carries your POTS (Plain Old Telephone System) telephone signals into your house also carries enough electricity (48v DC) from the telco Central Office to power the phone’s core elements of the headset, dial, and ringer. The latest PoE standard is 802.3at.

See part 1 here.

can cut installation costsPoE end devices (PD) became popular with the bean-counters because these devices can cut installation costs by as much as 90% over traditional powering techniques. With cost savings comes demands for new products however, the power limitation of 802.3af  prevented full support of  “high power” devices via the industry-standard PoE. In September 2005, the IEEE launched a task force to begin reviewing new PoE specifications to enhance the IEEE 802.3af guidelines into a next-generation standard.

The IEEE ratified the new PoE standard in 2009 called IEEE 802.3at-2009 PoE standard (aka PoE+ or PoE plus). Under the new standard Power Sourcing Equipment (PSE) must provide at least 30.0 Watts at the PSE port and 25.5 watts continuous power to up to 100 meters from the PSE over Cat5e or better cable to each PD. This will allow PoE to address applications such as multi-radio wireless APs, Pan-Tilt-Zoom (PTZ) gimbal-mounted cameras, 802.16 subscriber stations, 3G/LTE femtocells, perimeter security equipment, videoconferencing products, thin clients, and even some notebooks, as well as emerging applications. The new standard also provides full backward compatibility and interoperability to existing 802.3af compliant PSE’s and PD’s.

802.11n Wi-Fi technologyThe widespread use of 802.11n Wi-Fi technology has been one of 802.3at’s drivers. The multiple-input/multiple-output (MIMO) architecture used by 802.11n technology requires more power than earlier technologies, like 802.11a and 802.11b/g.

Installation practices and cable type impact the ability to use PoE+ to power a PD. Installation practices are outside the scope of the IEEE 802.3at standard. The Telecommunications Industry Association (TIA) has addressed these issues in a Telecommunications Systems Bulletin (TSB). TSB-184, Guidelines for Supporting Power Delivery Over Balanced Twisted-Pair Cabling describes how the impact of environmental conditions of the installed cabling and heat dissipation profiles of the cables’ effect the telecommunications cabling capacity to support the PoE+ application.

But Wait There’s More

IEEE logoOne of the most important benefits of the IEEE 802.3at standard is it incorporates existing 802.3af PoE safety requirements. The new standard includes compliance detection features for safe powering as well as safe PD disconnection in overload, short-circuit or under-load conditions enabling fast and safe adoption of the new standard.

The definition of a powered device changed under the IEEE 802.3at-2009 standard. The new standard considers the PD to be the powered interface, as opposed to the entire device being powered. This means that one device can have two power interfaces, each taking 25.5W, inside the same box. Nothing precludes these to be connected—one over the two pairs using lines 1, 2, 3, and 6 and the other over the two pairs using lines 4, 5, 7, and 8. This is what makes it possible to double the standard 802.3at-2009 maximum of 25W and go up to 51W while fully complying with the standard. Applications that need 51W PoE are an exterior IP camera with a heater or an access control system that includes a controller, a reader, and a few door locks which can easily consume 45W of power or more.

POE PTZ cameraAnother way PoE system developers are addressing the growing device powering requirements is by employing the option in the IEEE standard to add PoE functionality over all four pairs of the Ethernet cable. This option opens the door for safely delivering 60 watts of direct current (DC) power over a single Ethernet cable, using current levels of 600 milliamps (mA) than the 1.2 Amp level of two-pair 60W midspans.

The manufacturers claim this configuration can cut power consumption by 15% compared to two-pair solutions. This could translate into savings of about $25 per year per powered device, assuming energy costs of $0.10 per kilowatt-hour.

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  • IEEE Introduces Groundbreaking Standard for Body Area Networking (sys-con.com)

 

Ralph Bach has been in IT long enough to know better and has blogged from his Bach Seat about IT, careers, and anything else that catches his attention since 2005. You can follow him on LinkedIn, Facebook, and Twitter. Email the Bach Seat here.

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| April 5, 2012
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Power over Ethernet 802.3af

Power over Ethernet 802.3afA client recently asked what happened to the network design rule of thumb which said do not install data cables anywhere near electrical cables? The fear of cross-talk, interference, and corruption of the data traffic seems to have disappeared with Power over Ethernet (PoE). He rightly pointed out that now it seems OK to mix data and power in the same cable going to a networked device. 

Read part 2 here.

Plain Old Telephone SystemPoE is similar in principle to the way that the copper wire pair that carries your POTS (Plain Old Telephone System) telephone signals into your house also carries enough electricity (48v DC) from the telco Central Office to power the phone’s core elements of the headset, dial, and ringer. Power over Ethernet’s development started with early implementations of Voice over Internet Protocol VoIP)phone systems. VoIP pioneers did not have a telco CO to power the phones and powering the VoIP phones with wall warts proved unreliable. The phones stopped working when unplugged from the wall or if the building lost power.

In 2000 Cisco (CSCO) developed the first successful technique of putting 48v DC on the LAN data cable along with the data traffic. This proprietary system allowed Cisco to overcome customer objections to wall warts and sell a lot of VoIP systems.

Cisco logoCisco’s original PoE equipment was capable of delivering up to 10W per port. The endpoint and the Cisco switch negotiated the amount of power to be delivered based on a power value in the proprietary Cisco Discovery Protocol (CDP). The Power Sourcing Equipment (PSE) will send a Fast Link Pulse (FLP) on the transmit pair. The Powered Device (PD) connects the transmit line to the receiving line via a low pass filter. And thus the PSE gets the FLP in return. Cisco’s original PoE implementation is not software upgradeable to the IEEE 802.3af standard. Cisco manufactured many IP phones and WLAN access points devices that were not compliant with the IEEE 802.3-2005 Clause 33 including:

Cisco pre-standard IP phones
7985G7960G7940G7910G7910G + SW
7912G7905G7902G7970G
Cisco IEEE 802.3af and pre-standard IP phones
7970G7961G7906G7941G
7911G7962G
The Cisco 7936 Conference Phone does not support any LAN based power and requires a Cisco power injection adapter
Source

Throughout 2001 and 2002, other VoIP and Wireless Access Point (WAP) vendors saw Cisco’s success and developed their own proprietary (and often non-interoperable) powering systems. As more proprietary systems were developed the Institute of Electrical and Electronics Engineers (IEEE) recognized the need to standardize PoE. The IEEE 802.3 Ethernet Committee assigned PoE technology to a new working subcommittee called 802.3af. The IEEE working group’s charge was to create a standardized version of the Power Over Ethernet so that any manufacturer who wanted to could make their products PoE ready. The IEEE working group took commentary from 2001 to 2003 and released the ratified IEEE 802.3af-2003 Power over Ethernet standard in June 2003 which added clause 33 to the IEEE 802.3 standard

Institute of Electrical and Electronics Engineers (IEEE) 802.3 Ethernet CommitteeThe 802.3af document describes how PoE systems should work.  The standard defines two types of PoE equipment, Power Sourcing Equipment (PSE) and the Powered Device (PD). Power Sourcing Equipment sends the power out over the LAN cabling system to the Powered Device. The PSE would send out a maximum of 15.4 watts DC per link to each device, (limited to standard Ethernet distances). 12.95 watts are assumed to be available at the PD because some power is lost in the cable.

The nominal voltage is 48 V, over two of the four available pairs on a Cat. 3/Cat. 5e cable. “Phantom power” is used to allow the powered pairs to also carry data. This permits PoE to be used with 10BASE-T and 100BASE-TX, which use only two of the four pairs in the cable, but also with 1000BASE-T (gigabit Ethernet), which uses all four pairs for data transmission. This is possible because all versions of Ethernet over twisted pair cable specify differential data transmission over each pair with transformer coupling; the DC supply and load connections can be made to the transformer center-taps at each end. Each pair thus operates in “common mode” as one side of the DC supply, so two pairs are required to complete the circuit. The polarity of the DC supply may be inverted by cross cables; the powered device must work with either pair: spare pairs 4-5 and 7-8 or data pairs 1-2 and 3-6. Polarity is required on data pairs and ambiguously implemented for spare pairs, with the use of a bridge rectifier. (Source)

VOIP devicesPower Sourcing Equipment can be in two form factors. A PSE can be implemented as an endspan which is an Ethernet switch with powered ports (a PoE enabled switch) or midspan which is a power hub that is used along with a non-powered switch the end-user already has in place. PD’s can receive PoE equally well from either type of PSE per the standard. The decision to use an endspan or a midspan is left up to the end-user.  The end device can use either powering technique.

The Powered Device (PD) is a network device like VoIP phones, Wireless Access Points, and IP cameras. which are capable of taking the power off the LAN cable, through the RJ-45 (8P8C) connector and using it to power itself. Some pre-standard PoE devices are incompatible with 802.3af equipment. More PoE ready PD’s are available every year  PoE ready end devices can reduce installation costs by as much as 90% over traditional powering techniques.  Among the newer PoE PD’s devices on the market or coming soon are IP Paging, Speaker Systems, POS Terminals, Door and Gate Security hardware, Public Information signs, Building Access, Temperature Control Systems, Stage Lighting, and Computers. These newer PD’s were pushing 802.3af to its limits and the IEEE began work to evolve the standard. This power limitation prevented “high power” devices that required up to 30W to be supported via the industry-standard PoE solution.

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Ralph Bach has been in IT long enough to know better and has blogged from his Bach Seat about IT, careers, and anything else that catches his attention since 2005. You can follow him on LinkedIn, Facebook, and Twitter. Email the Bach Seat here.

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| September 20, 2011
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Super-Fi OK’d by IEEE

Super-Fi OK'd by IEEEI usually don’t have a problem getting a wireless signal where in my Bach Seat. However, there are some areas where I coordinate technical services that don’t get wired or wireless Internet. In these rural areas, where AT&T (T), Verizon (VZ), Sprint Nextel (S), and Comcast (CMCSA) and their fellow travelers fear to tread because they can’t make a buck in these areas, some help may be on the way from the IEEE.

IEEE logoIn 2009, the Institute of Electrical and Electronics Engineers (IEEE) started the development of IEEE standard 802.22, which addressed the need for broadband wireless access in rural areas, those where it is not economical to deploy a wired infrastructure. In July 2011, the IEEE announced that it has published the standard titled: “IEEE 802.22-2011 Standard for Wireless Regional Area Networks in TV Whitespaces” (PDF).

The IEEE press release states: “This new standard for Wireless Regional Area Networks (WRANs) takes advantage of the favorable transmission characteristics of the VHF and UHF TV bands to provide broadband wireless access over a large area up to 100 km (60 miles) from the transmitter. Each WRAN will deliver up to 22 Mbps per channel without interfering with reception of existing TV broadcast stations, using the so-called white spaces between the occupied TV channels.”That part of the spectrum, known as white spaces, sits between broadcast TV channels and will become available when broadcast TV stations switch from analog to digital in 2009.

VHF and UHF TV bands to provide broadband wireless accessThe White Space Coalition led by Microsoft (MSFT), Google (GOOG), Dell (DELL), and other tech titans strongly support the use of the white spaces in the U.S., going up against strong opposition lead by Michigan’s own John Dingell and big media like the NFL, MLB, NASCAR, NBA, NHL, NCAA, PGA Tour and ESPN who say unlicensed devices in the TV bands would interfere with their signals.IEEE 802.22 reportedly will not interfere with TV broadcasts, because it incorporates advanced cognitive radio capabilities including:

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I met Mr. Dingell about a dozen years ago, at a school to encourage the politician to support schools when the USF started the eRate program for schools. I recall Mr. Dingell telling me he could not support eRate because he did not trust the FCC to get it right. At least he is consistent.

I believe there is a very good chance this technology will never be a commercial success. The wireless carriers will squash this technology like they have squashed municipal wi-fi and community fiber networks. The improved speeds and coverage areas are a threat to their limited 4G coverage and they would lose out on their monthly pound of flesh capped rate-limited data plan.

It will be up to us in the public sector to implement this technology for our clients.

What do you think?

Will Super-Fi ever see the light of day?

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Ralph Bach has been in IT long enough to know better and has blogged from his Bach Seat about IT, careers, and anything else that catches his attention since 2005. You can follow him on LinkedIn, Facebook, and Twitter. Email the Bach Seat here.

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| February 19, 2011
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Hackers Can Target Cars

Hackers Can Target CarsWired reports that over 100 drivers in Austin, TX found their cars disabled or the horns honking out of control. This happened after an intruder ran amok in a web-based vehicle-immobilization system called Webtech Plus (PDF). Webtech Plus is normally used to get the attention of consumers delinquent in their auto payments. The app is operated by Cleveland-based Pay Technologies system. It allows car dealers to install a black box in the vehicle that responds to commands issued through a central website and relayed over a wireless pager network.

How he got in

Austin police claim the perpetrator was Omar Ramos-Lopez, a former Texas Auto Center employee who was laid-off. The hacker allegedly sought revenge by bricking the cars sold from the Austin-area dealership. Reportedly Mr. Ramos-Lopez’s account was closed when he was terminated but he allegedly got in through another employee’s account. At first, the intruder targeted specific customers. The attacker later moved to access the database of all 1,100 customers whose cars were equipped with the device. It is charged that he went through the database, vandalizing the records, disabling the cars, and setting off the horns.

Cars are targets

The Webtech attack was an external attack but Bob Brammer, CTO, and VP at Northrop Grumman Information Systems (NOC)  told GovInfo Security that cars themselves are likely to become targets. Mr. Brammer points out that most cars contain 50 to 100 or more tiny computers. The computers are controlled by over 100 megabytes of code that control the accelerator, brakes, displays, steering, etc. All of these systems can be accessed through a diagnostic port that serves as the vehicles’ USB port. Mr. Brammer cites a study published in an IEEE journal. “It’s possible to take over a car, controlling the brakes, the accelerator, the steering wheel, despite whatever the driver might want to do. Our automobiles are highly vulnerable from a cybersecurity view.”

The paper, Experimental Security Analysis of a Modern Automobile, (PDF) says the potential attack window could widen as more automakers offer vehicle-to-vehicle and vehicle-to-infrastructure communications networks to third-party development, “An attacker who is able to infiltrate almost any electronic control unit can leverage this ability to completely circumvent a broad array of safety-critical systems.”  GigaOm cites data from iSuppli that Wi-Fi in automobiles will be integrated into 7.2 million cars by 2017.

The researchers said they took control of a number of the car’s functions and the driver could do nothing about it. They bypassed basic network security protections within the car. They then embedded malicious code in the telematics unit to erase evidence of the hack’s presence after a crash.

More theoretical than practical

I luv your PCMr. Brammer, for now, sees the threat to cars as more theoretical than practical. But he says it demonstrates that we must think about cyber-security more broadly than we have in the past. “As the trend is to put more IT into everything that we do – whether it’s cars, airplanes, power grids, water supplies, whatever – we have to think about the security aspects of the design. These systems, within reason, have to be able to withstand certain types of attempts to attack or exploit them. That’s a terrible thing have to say, but I think that’s the way world is these day.”

Wi-Fi can give attackers an entry point into critical systems. Professor Stefan Savage of the University of California, San Diego told Technology Review. “In a lot of car architectures, all the computers are interconnected, so that having taken over one component, there’s a substantive risk that you could take over all the rest of them. Once you’re in, you’re in.” This could lead to brakes failing or the steering wheel seizing on scores if not hundreds of cars simultaneously, causing catastrophic crashes.

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Cars have become more computerized. They are linked through Wi-Fi and 3G networks making our daily transportation vulnerable to hackers and cyber-attacks. Cyber-terrorists could target cars to begin the chain of events leading to a Hollywood-style disaster. Hopefully, the Auto manufacturers are going to tighten up the security of our cars. They will delay improving security if safety belts and airbags are examples.

Will the auto industry tighten the security onboard cars?

Will the government have to step in?

 

Ralph Bach has been in IT long enough to know better and has blogged from his Bach Seat about IT, careers, and anything else that catches his attention since 2005. You can follow him on LinkedIn, Facebook, and Twitter. Email the Bach Seat here.

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| February 17, 2010
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Wireless Gigabit

WiGig AllianceThe Wireless Gigabit Alliance has completed specs for a technology designed to deliver as much as 7 Gbps of wireless bandwidth in the 60 GHz band. The new technology, WiGig has the support of technology giants such as Intel, Broadcom, and Atheros. The technology is expected to have enough capacity to deliver high-def video streams up to 10 meters. WiGig’s anticipated road map includes system certifications in 2010 and WiGig based products to market in 2011.

Supplement other wireless technologies

According to the WGA, WiGig is not designed to replace 802.11 or Bluetooth but rather to supplement it. WiGig is a device-to-device (p2p) network and does not need a central hub or router that could easily turn into a congestion point. WiGig uses beamforming to extend its range beyond the 10-meter range and will automatically switch to 802.11n Wi-Fi.  “Our technology is backward compatible with existing Wi-Fi, and we fall back to 802.11n and 802.11g when we can’t connect at [7 Gbps] speeds,” Ali Sadri, told TechNewsWorld. “We’re based on 802.11, so our spec is not replacing Wi-Fi but extending it to 10 to 20 times faster than Wi-Fi.”

“By complementing Wi-Fi and enabling multi-gigabit speeds, the versatile specification is a very significant achievement on the road to the next generation of wireless LAN products,” says Craig Mathias, a Principal with the wireless and mobile advisory firm Farpoint Group.

Integrate WiGig into Wi-Fi chipsets

It is reported that Intel, Broadcom, and Atheros all have plans to integrate WiGig into Wi-Fi chipsets. “Ultimately, the question is how many different kinds of radios do you really need?” says Farpoint’s Mathias, “There’s not just competition from Wi-Fi and wireless HD but also cellular technologies such as 3G, LTE or WiMax … A lot of people anticipate 60 GHz products that will include 2.4 and 5 GHz Wi-Fi as well,” said Bill McFarland, chief technology officer of Atheros, and a WiGig member. “I definitely think we can support tri-band at 65 nm,” he added.

WiGig will include protocol adaptation layers to support specific system interfaces including data buses for PC peripherals and display interfaces for HDTVs, monitors, and projectors. WiGig will include advanced security and power management for WiGig devices. “We’re rapidly paving the way for the introduction of the next generation of high-performance wireless products – PCs, mobile handsets, TVs and displays, Blu-ray disc players, digital cameras, and many more,” said Doctor Ali Sadri of Intel and president and chairman of the Wireless Gigabit Alliance

The need for fast wireless data transfer plays into two big trends: the proliferation of multimedia and the increasing cable clutter that users have to deal with. “NVIDIA recognizes the general market trend toward wire-free interfaces. Today, display interfaces are at an inflection point where the next generation solutions will feature wireless display connections for PCs, game consoles, notebooks, and mobile devices with PC monitors and TVs,” said Devang Sachdev, Technology Marketing Manager at NVIDIA and WiGig Board Member.

60 GHz loses strength quickly

The biggest knock against WiGig is that signals at 60 GHz get absorbed by oxygen, meaning they lose strength quickly. Steel or concrete walls and even people in the room can be degraded or stop the 60 GHz signal. However, Intel’s Sadri says there is a solution. A 60 GHz antenna is just 2.5 millimeters long,  small enough that a lot of them can be packed into even a thin TV set or a mobile handset. Put 32 antennas on the transmitting and receiving ends, and you can send enough steered beams to compensate for the losses the signal experiences over distance.

In the 60 GHz spectrum, WiGig is likely to run into some competition. The IEEE is introducing a follow-up to 802.11n Wi-Fi standards called 802.11ad.  The IEEE 802.11ad standard will also be based on the 60 GHz spectrum but is not expected before 2012.  Mathias says, “The WiGig Alliance hopes to get a head start now and they might submit their standard to the 802.11ad group to be included in the specification.” The Wireless HD consortium also supports a third 60-gigahertz wireless networking plan for uncompressed HD video. Sony and Samsung are backers of all three 60 GHz plans.

It is likely that IEEE 802,11ad and Wireless HD will find it hard to compete against a general-purpose WiGig standard that can do uncompressed wireless HD video and more.

Members of the WGA include:·

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Ralph Bach has been in IT long enough to know better and has blogged from his Bach Seat about IT, careers, and anything else that catches his attention since 2005. You can follow him on LinkedIn, Facebook, and Twitter. Email the Bach Seat here.

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