Welcome!

Java IoT Authors: Yeshim Deniz, Elizabeth White, Liz McMillan, Zakia Bouachraoui, Pat Romanski

Related Topics: @ThingsExpo, Mobile IoT, Agile Computing

@ThingsExpo: Blog Post

Difference Between Data Sheet Transmit Power & Data Stream Transmit Power | @ThingsExpo #IoT

Data Sheet Transmit Power & Data Stream Transmit Power

You need to link a two production sites together in your IIoT network in order to move critical voice, video, data and sensor data (VVDSTM) between the sites by deploying access points. So, you consider using industrial Wi-Fi Access Points to implement this short-haul, point-to-point (PTP) RF link between the two sites. Short-haul RF links out to 8 miles are very doable using industrial Wi-Fi Access Points with directional antennas.

You evaluate potential Wi-Fi Access Points from their data sheet specs. This is given, and you select one.

Header Image

Image courtesy of Flickr Creative Commons

Now, there is one specification that is commonly misunderstood and leads to confusion when evaluating MIMO capable Wi-Fi Access Points and using them in either PTP or point-to-multipoint (PMP) IIoT networks as wireless infrastructure.

Confusion and mistakes arise from the difference between the transmit power stated on the product data sheet and the transmit power of a single MIMO data stream of the Access Point.

For example, a 3×3 MIMO Access Point data sheet states the transmit power is 27dBm for MCS4/12/20 data encoding in either the 2.4 or 5GHz band.

This is typical, and not a surprise, but what is this transmit power really stating.

The FCC limits and regulates maximum transmit power from an intentional emitter, e.g. Wi-Fi Access Points. For Wi-Fi devices, the limits apply to the aggregate transmit power of the device. In above product spec example, the transmit power stated is the aggregate transmit power for the 3 MIMO data streams.

Still good? Yes. You have a Wi-Fi Access Point and the total transmit power is 27dBm.

Now, you design your short-haul PTP link using Wi-Fi Access Points and directional antennas.

What transmit power do you use in your RF link budget?

27dBm since it is the transmit power for the Access Point for the data encoding and the band you plan to use. Right?

No.

While 27dBm is the total aggregate transmit power for the Access Point, it is not the transmit power of an individual data stream. The individual data stream transmit power is roughly 5dB less than the aggregate transmit power found in the data sheet for a 3×3 MIMO product.

Difference in Transmit Power versus Aggregate Power

  • 1 Data Stream transmitting at 22dBm    -  Aggregate Transmit Power is 22dBm
  • 2 Data Streams transmitting at 22dBm  -  Aggregate Transmit Power is 25dBm
  • 3 Data Streams transmitting at 22dBm  -  Aggregate Transmit Power is 27dBm

So here it is...

If you use the transmit power from the data sheet in your RF link calculation without correction, your actual link distance will be approximately half what you expect for the planned fade margin or the link reliability will be less than what you expect for the planned link distance.

When designing RF links for the IIoT networks, make certain you are using the correct transmit power in your RF link budget calculations.

More Stories By Scott Allen

Scott is an executive leader with more than 25 years of experience in product lifecycle management, product marketing, business development, and technology deployment. He offers a unique blend of start-up aggressiveness and established company executive leadership, with expertise in product delivery, demand generation, and global market expansion. As CMO of FreeWave, Scott is responsible for product life cycle/management, GTM execution, demand generation, and brand creation/expansion strategies.

Prior to joining FreeWave, Scott held executive management positions at Fluke Networks (a Danaher Company), Network Associates (McAfee), and several start-ups including Mazu Networks and NEXVU Business Solutions. Scott earned his BA in Computer Information Systems from Weber University.

IoT & Smart Cities Stories
Cloud-enabled transformation has evolved from cost saving measure to business innovation strategy -- one that combines the cloud with cognitive capabilities to drive market disruption. Learn how you can achieve the insight and agility you need to gain a competitive advantage. Industry-acclaimed CTO and cloud expert, Shankar Kalyana presents. Only the most exceptional IBMers are appointed with the rare distinction of IBM Fellow, the highest technical honor in the company. Shankar has also receive...
DXWorldEXPO LLC announced today that ICOHOLDER named "Media Sponsor" of Miami Blockchain Event by FinTechEXPO. ICOHOLDER gives detailed information and help the community to invest in the trusty projects. Miami Blockchain Event by FinTechEXPO has opened its Call for Papers. The two-day event will present 20 top Blockchain experts. All speaking inquiries which covers the following information can be submitted by email to [email protected] Miami Blockchain Event by FinTechEXPOalso offers sp...
DXWordEXPO New York 2018, colocated with CloudEXPO New York 2018 will be held November 11-13, 2018, in New York City and will bring together Cloud Computing, FinTech and Blockchain, Digital Transformation, Big Data, Internet of Things, DevOps, AI, Machine Learning and WebRTC to one location.
@DevOpsSummit at Cloud Expo, taking place November 12-13 in New York City, NY, is co-located with 22nd international CloudEXPO | first international DXWorldEXPO and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time t...
Headquartered in Plainsboro, NJ, Synametrics Technologies has provided IT professionals and computer systems developers since 1997. Based on the success of their initial product offerings (WinSQL and DeltaCopy), the company continues to create and hone innovative products that help its customers get more from their computer applications, databases and infrastructure. To date, over one million users around the world have chosen Synametrics solutions to help power their accelerated business or per...
When talking IoT we often focus on the devices, the sensors, the hardware itself. The new smart appliances, the new smart or self-driving cars (which are amalgamations of many ‘things'). When we are looking at the world of IoT, we should take a step back, look at the big picture. What value are these devices providing. IoT is not about the devices, its about the data consumed and generated. The devices are tools, mechanisms, conduits. This paper discusses the considerations when dealing with the...
Charles Araujo is an industry analyst, internationally recognized authority on the Digital Enterprise and author of The Quantum Age of IT: Why Everything You Know About IT is About to Change. As Principal Analyst with Intellyx, he writes, speaks and advises organizations on how to navigate through this time of disruption. He is also the founder of The Institute for Digital Transformation and a sought after keynote speaker. He has been a regular contributor to both InformationWeek and CIO Insight...
Machine learning has taken residence at our cities' cores and now we can finally have "smart cities." Cities are a collection of buildings made to provide the structure and safety necessary for people to function, create and survive. Buildings are a pool of ever-changing performance data from large automated systems such as heating and cooling to the people that live and work within them. Through machine learning, buildings can optimize performance, reduce costs, and improve occupant comfort by ...
Digital Transformation is much more than a buzzword. The radical shift to digital mechanisms for almost every process is evident across all industries and verticals. This is often especially true in financial services, where the legacy environment is many times unable to keep up with the rapidly shifting demands of the consumer. The constant pressure to provide complete, omnichannel delivery of customer-facing solutions to meet both regulatory and customer demands is putting enormous pressure on...
Bill Schmarzo, Tech Chair of "Big Data | Analytics" of upcoming CloudEXPO | DXWorldEXPO New York (November 12-13, 2018, New York City) today announced the outline and schedule of the track. "The track has been designed in experience/degree order," said Schmarzo. "So, that folks who attend the entire track can leave the conference with some of the skills necessary to get their work done when they get back to their offices. It actually ties back to some work that I'm doing at the University of San...