guide report - wireless fundementals v1.0 150114

Guide Report: Wireless Fundamentals Copyright © 2014 RMAC Technology Partners, Inc.

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Guide Report:

Wireless Fundamentals The Fundamentals and History of Wireless.

Wireless Strategy & Business Development for the Connected World


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Attribution

Executive Editor: Clay Melugin Authored by Clay Melugin Contributors: Jim Riley, Gary Lizama, Tim Medved, Janet Larson Quality Assurance: Clay Melugin Published by RMAC Technology Partners, Inc. Copyright © 2014 RMAC Technology Partners, Inc. San Diego, California 92130 All rights reserved. No part of this book may be reproduced, in any form or by any means, without permission in writing from the publisher. Printed in the United States of America

Disclaimer RMAC Technology Partners, Inc. has made every reasonable effort to ensure that all information in this report is correct. We assume no responsibility for any inadvertent errors.

Revisions: 1/14/2015 v1.0 – Initial Public Release

Table of Contents 1 Report Overview ........................................................................................................................... 4

2 History of Wireless ...................................................................................................................... 5

3 Wireless Modems -‐ Essential Elements ................................................................................. 7 3.1 Basic Block Diagram ..................................................................................................................... 7 3.2 Basic Elements ................................................................................................................................ 7

4 Wireless Communication ........................................................................................................... 9 4.1 How Wireless Works ..................................................................................................................... 9

5 Modulation .................................................................................................................................. 11 5.1 Amplitude Modulation (AM) .................................................................................................... 11 5.2 Frequency Modulation (FM) ..................................................................................................... 12 5.3 Frequency Shift Keying (FSK) .................................................................................................. 13 5.4 Phase Shift Keying (PSK & QPSK) ........................................................................................... 14 5.5 CDMA ................................................................................................................................................ 16 5.6 OFDM ................................................................................................................................................ 17

6 Performance – Distance .......................................................................................................... 18

7 Networks ...................................................................................................................................... 20 7.1 Private Networks & Spectrum ................................................................................................. 20 7.2 Public Networks & Spectrum ................................................................................................... 20

8 Spectrum & Regulatory ........................................................................................................... 21 8.1 Government Auctions & Allocation ........................................................................................ 21 8.2 Regulatory Control ...................................................................................................................... 21 8.3 Certification ................................................................................................................................... 21 8.4 Approvals ........................................................................................................................................ 22

8.4.1 Cellular Network Operator Approvals ................................................................................... 22 8.4.2 Public / Open Networks Approvals ........................................................................................ 22 8.4.3 Private Networks Approvals ...................................................................................................... 22

9 Industry Standards Technologies ........................................................................................ 23 10 Proprietary Technologies ....................................................................................................... 24


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1 Report Overview This report provides a fundamental overview of wireless technology basics of operation, general terminology, essential elements and a history of the evolution of wireless. It is for users who have no prior technical experience with wireless but would like to get a basic understanding of wireless. Today's modern wireless devices and technology operate based on the same fundamentals of physics as the earliest wireless devices, but they have evolved as standards of operation have enabled greater functionality. By understanding the basics of wireless and its history you will see through the many confusing terms and jargon that prevails in the industry today, and view these new systems as simply standardization of basic wireless operation to enable the interoperability of wireless devices. Armed with a basic understanding of wireless enables you to view the wide variety of wireless standards as a simple process of selecting the appropriate wireless technology to match the product goals. The selection of a wireless technology for a product solution is based on a number of factors such as;

• Functional requirements • User requirements • Interoperability

• Product cost • Operating cost • Life cycle cost

This report takes away the mystery of wireless so you can focus on selecting a wireless standard that best suits your solution needs. After reading this report check out the next step:

Guide Report: Wireless Technology Landscape Overview of Wireless Technologies used in IoT/M2M Connected Devices Highlighting the capabilities of Wireless Network Standards for wireless communication.

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Guide Report: !

Wireless!Technology!Landscape!Overview!of!Wireless!Technologies!used!in!IoT/M2M!Connected!Devices.!

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2 History of Wireless The ability to send information invisibly and silently began with the efforts of a few individuals who dedicated their lives to understanding and predicting the nature of the world around them based upon the curious nature of electricity.

1867 Maxwell predicted the existence of electromagnetic waves. 1887 Hertz proved electromagnetic waves exist by sending data

several meters away using a spark transmitter and receiver. 1896 Marconi’s demonstration of wireless telegraphy. 1897 The birth of the word “Radio”. 1902 Radio signals capable of crossing the Atlantic. 1914 The world entered a whole new era with voice over the radio

greatly improving the ability to share information. 1920s Adoption of Radio technology into police cars in Detroit. 1930s RADAR systems are discovered and developed to enable

detection of objects far away by the reflection of radio wave energy.

1940 FM radio successfully demonstrated bringing greater quality to

audio signals. 1943 RADAR systems begin to deploy in the military early warning

systems. 1946 First Mobile phone calls to PSTN (Public Switched Telephone

Network), driving mobile wireless communication expansion to 1.4 million users in the 1960’s with demand far higher, but the airwaves were too crowded to support more users.

1957 Emergence of man-‐made Satellites (Sputnik 1) orbiting the earth

opening up new dimensions of communication and observation. 1979 First cellular phone network deployed by NTT/Japan. 1984 Motorola brought the first cellular network to the US as AMPS

(American Mobile Phone System).


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1989 GSM becomes the world’s first digital mobile phone system leading to a worldwide expansion of digital cellular communications technology in 1990’s.

1995 I use my last payphone, and toss away my pager; CDMA based

phones emerge in the USA. 2000s Digital Cellular expansion grows explosively worldwide; wireless

solutions such as WiFi, DECT and Bluetooth fill the gap. Standards emerge to ‘cut the cords’ and offload capacity just as the smartphone boom happens making the workplace more mobile.

2007 Apple launches a revolution with the first commercially

successful touchscreen Smartphone, driving wireless capacity to the edge of capacity overload, and changing customer perception of how the world can be connected.

2010 LTE technology and networks deployed to deliver high-‐speed,

high capacity mobile data networks.

While wireless signaling approaches continue to enable new devices, many simple wireless approaches from 80 years earlier continue to operate effectively across the globe, and from the far reaches of space. Yet it is still the same basic principle of Electromagnetic waves that Maxwell predicted which is the base of all these technologies.


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3 Wireless Modems -‐ Essential Elements There are several essential elements in a typical wireless modem that are important to understanding the basic terminology. Becoming familiar with these elements will help you to evaluate the capability of each type of wireless technology available, thus making product design decisions easier to contemplate and incorporate.

3.1 Basic Block Diagram

3.2 Basic Elements Modem: The combined resources of the Protocol Stack, Baseband

Processors, and RF Transceiver that operate in concert to enable data to be sent and received over the wireless network by performing the Modulation and Demodulation of the RF signals.

Protocol Stack: Software that runs on the Baseband processor to control

the modem operation and interaction with the network. Baseband: The microprocessor used for network interaction timing,

encoding of data to be transmitted, and decoding of signals received.


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RF Transceiver: Integrated Circuit which contains the Transmitter & Receiver circuits that handle the conversion of signals to the frequency/bands, this device operates under control of the Baseband processor which is running the Protocol stack.

PA: Power Amplifier that increases the transmitted RF signal

strength. Antenna: A conductive metal device designed to radiate RF energy

at specific transmit and receive bands. Switch: Switches RF signals to different filter paths based on what

frequency band of operation is required. In some designs it also switches the antenna from Transmit to Receive paths at a scheduled interval.

Filters: Used to eliminate adjacent frequencies from interfering

with received signal, and to eliminate unintentional transmitting of signals outside the allowed frequency band.

Band(s): A specific frequency range designated for use in wireless

communications. Power Supply: Frequently designed into the wireless chipset to enable

tight control of power supply levels, these dedicated circuits eliminate variations in the voltage supply that would distort the transmitted or received signals.

Shielding: Metal enclosures that encase the modem circuits to

prevent unintended and unwanted radiation from escaping or entering the modem.


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4 Wireless Communication

4.1 How Wireless Works All electrical circuits emit electromagnetic radiation, the key is controlling them to a defined frequency spectrum we call the Radio Frequency (RF) spectrum, and directing the RF radiation towards the target where it is to be received. The Transmitter is an electronic circuit is designed to oscillate at a specific frequency, and the output is connected to an Antenna that has an ideal length of ¼ of a wavelength.

Wavelength = (Speed of light) ÷ ( Frequency of oscillation)

What happens when this circuit is designed properly?

Driven by the Transmitter output, all the free electrons on the Antenna move rapidly from end-‐to-‐end on the antenna in an orchestrated resonance matching the frequency of the Transmitter output. When the electrons move they create an electromagnetic wave (RF) that radiates away from the antenna at the speed of light (like ripples on a pond).

Modulation of the RF radiation enables sending data as an RF signal. Turning the Transmitter ON and OFF results in the RF radiation starting and stopping so binary data like Morse code can be transmitted as an RF signal. This is a basic form of Modulation used to create an RF signal that is radiated, similar to turning a flashlight ON and OFF.

3x 108 meter/second

(Speed of light)


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How a Receiver recovers the transmitted RF signal.

A matching ¼ wavelength antenna is exposed to the RF signal from the Transmitter Antenna. The RF signal energy resonates the Receiver Antenna and the electrons mimic the rapid motion of the transmitter antenna, creating an extremely small electrical signal (voltage) on the output of the antenna. In fact, this is a very small part of the same RF signal energy that was originally transmitted. The Receiver routes the signal through a Filter that allows only the desired RF signal to pass through to the Amplifier which then increases the RF signal strength to a useful level. The RF signal can then be demodulated to recreate the same pattern of ON/OFF that was transmitted and the information thus has been received.

While this is a simplification of the actual process used in many radios today, it is the basic process all radios use to send data wirelessly. The modulation, frequency control, signal timing, and network control systems to make this work reliably are complex and required years of engineering and standards development to ensure reliable wireless device interoperability.


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5 Modulation There are other forms of Modulation techniques that are used instead of the simple ON/OFF carrier signaling previously described. New modulation techniques are constantly being developed to improve the quality of the signal connections by reducing signal errors caused by external RF noise and to increase the amount of data throughput on a RF frequency band.

5.1 Amplitude Modulation (AM) In our simple modulation approach shown in Section 3.1 we were actually changing the transmitted signal power level and disrupting the continuous electromagnetic wave that would otherwise have existed to send data. If the Transmitter RF output was amplified proportional to an input signal (Voice),o then the Amplitude of the radiated RF signal would fluctuate in a corresponding manner.

A receiver could very easily recreate the original Voice signal by tracking the amplitude variation of the received RF signal. Such a solution was the basis of Amplitude Modulation (AM) that was widely used in the early days of Radio for broadcasting Voice and Music. It was revolutionary, but not perfect because outside energy from other sources like lightning or overhead power lines added extra signal energy, with bridges and tunnels causing decreases in signal energy creating distortion in the demodulated signal.


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5.2 Frequency Modulation (FM) Frequency Modulation is the direct variation of the transmitter signals frequency based on an input signal (Voice or Music) to be transmitted.

On the receiver side the variation in frequency is tracked to recreate the original input to the modulation. The advantage of FM modulation is that variations in the transmitted signal amplitude have no impact on the demodulated signal, eliminating distortion from external sources (lightning, power lines, bridges and tunnels as found in AM). Changes in FM signal strength have no impact on the frequency of the received signal. There is however a need to transmit and receive over a wider frequency band (compared to AM) making the receiver filter slightly more complicated, and the Antenna slightly less efficient.


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5.3 Frequency Shift Keying (FSK) Frequency Shift Keying was designed for transmitting data, not analog signals like voice or music (unless digitized). Here the transmitted frequency changes rapidly to mimic the data stream.

Data throughput with FSK designs is directly related to the operating center frequency of the transmitter, so operation at a higher frequency spectrum enables higher data transmission rates than its close cousin FM. Similar to FM, there are decreases in antenna efficiency, added complexity in filter design, and susceptibility to inherent signal noise that introduces data bit errors in the data stream. (Not noticeable in FM analog Voice/Music, but critical in Data streams as every data bit counts!) To overcome the data bit errors, the implementation of error detection and error correction coding is added to the data stream. This reduces the effective data transfer rate slightly and increases the digital processing required on both the transmitted and received digital data streams. Error detection and correction leads to data being formed into packets that include the error detection and correction codes. Packets that can’t be recovered with error correction are retransmitted on request.


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5.4 Phase Shift Keying (PSK & QPSK) To increase data throughput in the same frequency channel bandwidth Phase Shift Keying (PSK) was developed. PSK modulation is a digital modulation technique performed by changing the phase of the signal by 180 degrees when the data stream changes the bit value (0 or 1). Comparing the received signal to the reference signal and detecting the phase change performs PSK demodulation.

In QPSK the data stream is split into 2 paths (I & Q) and used to modulate each paths signal phase. Then the 2 signal paths are combined (added) together resulting in the signal to be transmitted (noted as QPSK signal below).


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Here the transmitted frequency is not changed, but the phase of each signal is suddenly shifted based on the next two bits of the data stream. Imagine a Sine waveform representing the transmitted signal, and suddenly the phase of the signal advances or retards by 90 or 180 degrees.

The receiver can separate the modulated streams, detect the phase changes and rebuild the original data stream the Transmitter used to create the signal. With QPSK you can observe how modulation techniques evolve toward more complex coding approaches to get increased amounts of data pushed through the same frequency channel. The advantage of QPSK is more bits-‐per-‐hertz of frequency spectrum. Electromagnetic spectrum is valuable real estate that needs to be used efficiently, or we run out of available frequency spectrum. PSK and QPSK are subject to noise that can create bit errors when the signal is received, so error detection and correction are commonly included in these packet-‐based data transmissions.


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5.5 CDMA Code Division Multiple Access (CDMA) modulation was commercialized for consumer applications by Qualcomm and it is FSK/QPSK on steroids, so I’ll keep it simple and obvious. The concept is simple;

o Transmit multiple data streams (Channels) on the same RF frequency.

o Establish a common synchronized time base for all devices. o Use the same code sequence for all devices. o Add a unique time offset to each data channel code. o Code each data channel using that unique offset. o Use a control channel so each device knows its code offset and stays

synchronized to network time. o Implement power control so received signal strength is the same

from all devices. The code (called Pseudorandom Code) repeats every 41.4 days, so there is plenty of room to separate the data channels and account for adjacent frequency channels too. The data stream is overlaid onto the Pseudorandom Code with a time offset, and then all the data streams transmit on the same frequency band at the same time. Most important is that each data channel stream on the same frequency channel is using a unique part of the same Pseudorandom Code, so no two devices use the same part of the Pseudorandom Code at the same time on the same network.

Receivers decode the RF signal by knowing;


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o Frequency channel o Pseudorandom Code offset o Accurate time base – extremely important!

It works efficiently, and it uses packet data error detection and correction to resolve bit error problems. CDMA put a lot more data over the same spectrum than all previous modulation techniques making it an efficient network to operate (less frequency spectrum real estate to purchase). Disadvantages – Complexity increases the cost of the hardware solution. The CDMA payback is in lower data transfer costs on the network, which is a long-‐term advantage that lowers overall cost of ownership.

5.6 OFDM Orthogonal Frequency-‐Division Multiplexing is the modulation approach used in high-‐speed LTE networks. It’s another step up in modulation complexity and performance, demonstrating that technology evolution is alive and generating advances in modulation and coding to deliver increased performance (data rate) and higher spectral efficiency (lower operating cost). For more information on OFDM or many other modulation approaches not listed see the best website in the World. www.wikipedia.com


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6 Performance – Distance The distance over which a wireless connection can be made is dependent on multiple factors listed below in order of importance.

• Transmit Power • Receiver Sensitivity • Spectrum Frequency • Terrain

Transmit Power As the RF signal travels from the Antenna its energy spreads out over the surface area of a sphere as it travels (like an expanding balloon), exponentially decaying the signal energy (strength) as distance increases. Transmitted power output is the dominant factor in communication range. The greater the RF signal strength the farther it can travel before its energy dissipates below a detectable level. A 6dB (4x) increase in Transmit Power (if allowed) will roughly double the range of the wireless connection. All countries regulate maximum transmit power to control out-‐of-‐band noise impacts on other systems. Increasing transmit power may not be a viable option. Receiver Sensitivity How sensitive the receiver is to incoming signals is the 2nd dominant factor in communication distance. Sensitivity is a measure of how low (weak) the RF signal energy can be and still be detected and decoded by the Receiver. The more sensitive the receiver, the greater the effective range from the Transmitter, but receiver sensitivity well below the ambient noise level of the electromagnetic spectrum is not very effective and it’s subject to higher bit error rates. A 6dB (or 4x) increase in Receiver Sensitivity will roughly double the range of the wireless connection, only if the signal is above the ambient noise floor.


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Frequency The frequency of the RF signal impacts how far it can propagate (travel) through the atmosphere because RF interacts with elements (like water vapor) as it propagates, losing energy to the atmospheric elements. In general the higher the frequency, the more energy the atmosphere absorbs from the RF signal and the shorter the distance of useful communication. Water vapor interaction is significant in the microwave frequency range (2.4 GHz) where WiFi and Bluetooth operate in the ISM Band.


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7 Networks

7.1 Private Networks & Spectrum

A private wireless network restricts use to only authorized wireless devices. Typically these networks use commonly available approaches to modulation and network control and operate on a licensed frequency band that is exclusive to the owners. Keeping a network private is a matter of both legal and technical elements. First, it is illegal to use a frequency band that is licensed to another entity without permission. Second, wireless network operators commonly employ authentication technology to prevent unauthorized access to their network, and encryption technology for data/voice security.

7.2 Public Networks & Spectrum There is frequency spectrum set aside for open public operation. This spectrum can be used within well-‐defined guidelines and requirements. Users of open public spectrum can encrypt their data and operate a network that only supports their authenticated devices while not disabling other users from simultaneously using the same spectrum. Good examples of the Public Spectrum and Networks are:

• ISM • WiFi • Bluetooth

• ZigBee • RFID / NFC • Amateur Radio

Governments and organizations worldwide work together to enable public networks and to define standards of operation enabling users free and equal access to all users.


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8 Spectrum & Regulatory

8.1 Government Auctions & Allocation To operate a wireless device it is necessary to radiate electromagnetic energy within a designated frequency range (Frequency Band or Frequency Channel). The government of each country, international committees, and scientific and technical organizations collaborate to effectively and efficiently use the limited spectrum available everywhere on earth and in outer space. Governments auction spectrum (Frequency Bands) to buyers who want to operate public or private wireless networks. They also grant spectrum for a specific applications like RADAR, GPS, and ISM for usage on systems of public interest and benefit.

8.2 Regulatory Control Governments place strict limits on in-‐band and out-‐of-‐band RF emissions to ensure that devices operating in adjacent frequency bands or frequency channels do not interfere with other devices. OEMs (Original Equipment Manufacturers) of electronic and wireless devices are responsible for the adherence to these regulatory requirements.

8.3 Certification All electronic devices are subject to mandatory testing of radiated emission, even if they are not intentional radiators of electromagnetic energy. This certification testing helps prevent accidental jamming of spectrum by computers, stereos, garage door openers, microwave ovens, cellphones and other electronic devices sitting adjacent to each other. Wireless products that intentionally transmit RF must undergo far more rigorous certification testing to assure they don’t create interference inside or outside of intended operating bands under all operating conditions. Certification is a critical milestone to anyone developing a wirelessly connected device. It is not to be taken lightly as even previously proven wireless designs can fail certification testing unless knowledgeable care is taken in the design or modification of a product.


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8.4 Approvals After Government and Industry Standards Certification testing is completed, devices that operate on wireless networks are still subject to multiple approval processes.

o Network Operators (Carriers), o Infrastructure equipment manufacturers o Software systems that automate on Networks

8.4.1 Cellular Network Operator Approvals Cellular Networks Operators require all wireless devices to be tested by a certified testing labs to assure the devices meets industry standards, as well as comply with unique Network Operator default requirements. Operators review the certified test reports as part of their approval process, and may also run additional testing on new types of devices before granting approval to operate the devices on their network. Devices are subject to a periodic recertification process to monitor for compatibility to upgrades in the Operators network configuration.

8.4.2 Public / Open Networks Approvals Public networks which are open for any device or technology to operate also require certification testing as mandated by the government. This testing assures devices don’t interfere with other devices, or take over the spectrum in an unfair manner. Open network standards like WiFi, Bluetooth, and ZigBee fall into this category even though the networks are not typically open to all users, they can operate in the allocated open network spectrum.

8.4.3 Private Networks Approvals Private network operators may require Approval reviews and additional testing to ensure the devices operate within regulatory requirements, and testing to ensure the devices will not damage the network by disrupting or blocking usage by other customers. Approval by Private Network operators varies widely based upon how the technology ecosystem is managed.


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9 Industry Standards Technologies Wireless technology that is based on industry working group standards are designed to provide greater adoption and more competition in the delivery of interoperable system designs (like cellular, WiFi, and Bluetooth). Overall this approach has delivered the wireless standards that are most widely used today, and pricing of these standards-‐based designs is very competitive thus driving down consumer costs and increasing adoption worldwide. Many competing companies contribute significant efforts and Intellectual Property (IP) to the Standard development process. The Standards committee and working groups evaluate, select and prototype test contributed IP following an agreed upon process of design evaluation and member voting to define the standard. IP contributors agree upfront to allow any entity to use the contributed IP subject to RAND (Reasonable and Non-‐Discriminatory) payment of licensing fees directly to the IP owner outside of the Standards process. Some IP included in the Standard is declared “Essential IP” indicating that there is no way to be compliant to the Standard without licensing that particular IP. The most widely used wireless technologies are Industry Standards based system designs:

• Cellular • Wi-‐Fi • Bluetooth

• RFID • ZigBee


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10 Proprietary Technologies Wireless technology and networks can be developed without the creation of an industry standard. These types of proprietary network ecosystems can use either licensed or unlicensed spectrum for operation and deliver acceptable performance. The chipsets to support these networks are typically designed by the creators of the proprietary network, or instead they can use commonly existing wireless chipsets and only develop the network operation software. Sometimes groups of companies will collaborate to create these designs and share the rights to use within the closed group, or even license the rights to outside OEMs to incorporate the proprietary technology into their product. Advantages of proprietary systems are focused support and operations controlled by a single entity that profits from the continued operation of the system that usually provides long-‐term stability in the technology. Security on proprietary technology networks is frequently a talking point on advantages over open-‐access networks like Wi-‐Fi and Bluetooth. Proprietary technology networks profit from royalties, chipset sales and network usage fees. Pricing is under the control of the ecosystem owner and is subject to competitive pressure from other Proprietary and Standard based systems. Continued growth through market adoption is key to the long-‐term success of the proprietary ecosystem. The primary risk in using a proprietary solution is price competition in the future. While upfront incentives to get user adoption are common, the long term pricing of the chipsets and network usage is often at the discretion of the technology owner. Stability is common in these types of systems as the system design has generally evolved in a very consistent and controlled manner, but the risk of financial failure or long-‐term lack of competitive pricing is a factor to consider. Network coverage should be evaluated to determine if it meets requirements. Examples of Proprietary Technologies:

• Z-‐Wave • Insteon • X10 • SilverSpring Networks

• FlexNet • RPMA Network • Ant • ViaSat

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guide report - wireless fundementals v1.0 150114

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