6 Communication Protocols Used by IoT
The Internet of Things (IoT), is based on the networking of things. In a nutshell, Internet of Things is defined as a “proposed development of the Internet in which everyday objects have network connectivity, allowing them to send and receive data.”
The most important thing here is connectivity among objects.
Research companies like Gartner have predicted that Internet of Things will grow to 26 billion units in 2020. How will the devices be connected and what would communication be like? How will wireless communication protocols evolve?
We can boil down the wireless communication protocols into the following 6 standards:
In the following paragraphs, we will provide a brief overview and illustration of each of the Internet of Things communication techniques, their pros and cons, and their smartphone compatibilities.
Satellite communications enable cell phone communication from a phone to the next antenna of about 10 to 15 miles. They are called GSM, GPRS, CDMA, GPRS, 2G / GSM, 3G, 4G / LTE, EDGE and others based on connectivity speed.
In Internet of Things language, this form of communication is mostly referred to as “M2M” (Machine-to-Machine) because it allows devices such as a phone to send and receive data through the cell network.
Pros and Cons of Satellite Communication
- Stable connection
- Universal compatibility
- No direct communication from smartphone to device (It has to go through satellite)
- High monthly cost
- High power consumption
Example of satellite connectivity would include utility meters that send data to a remote server, commercials updated on digital billboards, or cars via Internet connectivity.
Satellite is useful for communication that utilize low data volumes, mainly industrial purposes but in the changing near future where cost of satellite communication is gradually falling, the use of satellite technology might become much more viable and interesting for consumers.
WiFi is a wireless local area network (WLAN) that utilizes the IEEE 802.11 standard through 2.4GhZ UHF and 5GhZ ISM frequencies. WiFi provides Internet access to devices that are within the range (about 66 feet from access point).
Pros and Cons of WiFi
- Universal smartphone compatibility
- Well protected and controlled
- Relatively high power usage
- Instability and inconsistency of WiFi
Example of WiFi connectivity would be Dropcam streaming live video via the local WiFi instead of streaming through a connected Ethernet LAN cable. WiFi is useful for many Internet of Things connections but such connections typically connect to an external cloud-server and are not directly connected to the smartphone. It is also not recommended for battery-powered devices due to its relatively high power consumption.
3. Radio Frequency (RF)
Radio frequency communications are probably the easiest form of communications between devices. Protocols like ZigBee or ZWave use a low-power RF radio embedded or retrofitted into electronic devices and systems.
Z-Wave’s range is approximately 100 ft (30 m). The radio frequency band used is specific to its country. For example, Europe has a 868.42 MHz SRD Band, a 900 MHz ISM or 908.42 MHz band (United States), a 916 MHz in Israel, 919.82 MHz in Hong Kong, 921.42 MHz in the regions of Australia/New Zealand) and 865.2 Mhz in India.
ZigBee is based on the IEEE 802.15.4 standard. However, its low power consumption limits transmission distances to a range of 10 to 100 meters.
Pros and Cons of RF
- Low energy and simplicity for its technology is not dependent on the new functionality of phones
- Radio frequency technology is not used by smartphones and without a central hub to connect the RF devices to the internet, the devices cannot be connected
Example of radio frequency connectivity would be your typical television remote for it uses radio frequency, which enables you to switch channels remotely. Other examples include wireless light switches, electrical meters with in-home displays, traffic management systems and other consumer and industrial equipment that requires short-range low-rate wireless data transfer.
Radio frequency communication protocol is useful for large deployments such as hotels where high quantity of devices are required to be centrally and locally managed. However, in the near future, the technology might become increasingly outdated and be replaced by Bluetooth mesh networks.
Radio frequency identification (RFID) is the wireless use of electromagnetic fields to identify objects. Usually you would install an active reader, or reading tags that contain a stored information mostly authentication replies. Experts call that an Active Reader Passive Tag (ARPT) system. Short range RFID is about 10cm, but long range can go up to 200m. What many do not know is that Léon Theremin invented the RFID as an espionage tool for the Soviet Union in 1945.
An Active Reader Active Tag (ARAT) system uses active tags awoken with an interrogator signal from the active reader. Bands RFID runs on: 120–150 kHz (10cm), 3.56 MHz (10cm-1m), 433 MHz (1-100m), 865-868 MHz (Europe), 902-928 MHz (North America) (1-12m).
Pros and Cons of RFID
- Does not require power
- Established and widely used technology
- Highly insecure
- Ongoing cost per card
- Tags need to be present as identifier and be handed over before
- Not compatible with smartphones
Examples include animal identification, factory data collection, road tolls, and building access. RFID tag is also attached to an inventory such that its production and manufacturing progress can be tracked through the assembly line. As illustration, pharmaceuticals can be tracked through warehouses. We believe RFID technology will very soon be replaced by near field communication (NFC) technology in smartphone.
Bluetooth is a wireless technology standard for exchanging data over short distances (using short-wavelength UHF radio waves in the ISM band from 2.4 to 2.485 GHz). If you look at the frequencies it is actually the same as WiFi such that these two technologies seem very similar. However they have different uses.The 3 different styles of Bluetooth technology that are commonly talked about are:
- Bluetooth: Remember the days where you associate Bluetooth as a battery drainer and black hole? Such Bluetooth are a heyday relic of a mobile past marked by bulky cell phone. Such Bluetooth technology are battery draining, insecure and are often complicated to pair.
- BLE (Bluetooth 4.0, Bluetooth Low Energy): Originally introduced by Nokia and presently used by all major operating systems such as iOS, Android, Windows Phone, Blackberry, OS X, Linux and Windows 8, BLE uses fast, low energy usage while maintaining the communication range.
- iBeacon: It is the trademark for a simplified communication technique based on Bluetooth technology that Apple uses. What it actually is: a Bluetooth 4.0 sender that transmits an ID called UUID, which is recognized by your iPhone. This simplifies the implementation effort many vendors would previously face. Moreover, even non-technically trained consumers can easily use iBeacons like Estimote.com or other alternatives. Although, different on a technical level, iBeacon technology can be compared to NFC on an abstract level.
Bluetooth exists in many products, such as telephones, tablets, media players, robotics systems. The technology is extremely useful when transferring information between two or more devices that are near each other in low-bandwidth situations. Bluetooth is commonly used to transfer sound data with telephones (i.e., with a Bluetooth headset) or byte data with hand-held computers (transferring files).Bluetooth protocols simplify the discovery and setup of services between devices. Bluetooth devices can advertise all of the services they provide. This makes using services easier, because relative to other communication protocols, it enables greater automations such as security, network address and permission configuration.
Comparison of Wifi & Bluetooth
Wi-Fi and Bluetooth are to some extent complementary in their applications and usage.
- Access point centered, with an asymmetrical client-server connection where it provides all traffic routed through the access point.
- Serves well in applications where some degree of client configuration is possible and high speeds are required e.g. network access through an access node
- Ad-hoc connections are possibe with WiFi but not as easily with Bluetooth for Wi-Fi Direct was recently developed to add a more Bluetooth-like ad-hoc functionality
- Symmetrical between two Bluetooth devices
- Serves well in simple applications where two devices are needed to connect with minimal configuratione.g. headsets and remote controls
- Bluetooth accesspoints do exist although they are not common
Any Bluetooth device in discoverable mode transmits the following information on demand:
- Device name
- Device class
- List of services
- Technical information (for example: device features, manufacturer, Bluetooth specification used, clock offset)
Pros & Cons of Bluetooth
- Every smartphone has Bluetooth where the technology is continuously being upgraded and improved through new hardware
- Established and widely used technology
- Hardware capabilities changes very fast and will need to be replaced
- Running on battery the lifetime of an iBeacon is between 1month to 2 years
- If people switch off Bluetooth, there are issues in usage.
Bluetooth technology mainly finds applications in the healthcare, fitness, beacons, security, and home entertainment industries.
Bluetooth technology is definitely the hottest technology right now but it is many times overrated or misunderstood in functionality. If the application goes beyond fun you will have to dig deep in configuration and different settings as different phones react differently to Bluetooth.
6. Near Field Communication (NFC)
Near-field communication uses electromagnetic induction between two loop antennas located within each other’s near field, effectively forming an air-core transformer. It operates within the globally available and unlicensed radio frequency ISM band of 13.56 MHz on ISO/IEC 18000-3 air interface and at rates ranging from 106 kbit/s to 424 kbit/s. NFC involves an initiator and a target; the initiator actively generates an RF field that can power a passive target (an unpowered chip called a “tag”). This enables NFC targets to take very simple form factors such as tags, stickers, key fobs, or battery-less cards. NFC peer-to-peer communication is possible provided both devices are powered.
There are two modes:
- Passive communication mode: The initiator device provides a carrier field and the target device answers by modulating the existing field. In this mode, the target device may draw its operating power from the initiator-provided electromagnetic field, thus making the target device a transponder.
- Active communication mode: Both initiator and target device communicate by alternately generating their own fields. A device deactivates its RF field while it is waiting for data. In this mode, both devices typically have power supplies.
Pros & Cons of NFC
- Offers a low-speed connection with extremely simple setup
- Can be used to bootstrap more capable wireless connections
- NFC has a short range and supports encryption where it may be more suitable than earlier, less private RFID systems
- Short range might not be feasible in many situations for it is currently only available on new Android Phones and at Apple Pay on new iPhones
Comparison of BLE to NFC
BLE and NFC are both short-range communication technologies that are integrated into mobile phones.
Speed: BLE is faster
Transfer: BLE has higher transfer rate
Power: NFC consumes less power
Pairing: NFC does not require pairing
Time: NFC takes less time to set up
Connection: Automatically established for NFC
Data transfer rate: Max rate for BLE is 2.1 Mbits/s, max rate for NFC is 424 kbits/s.
(NFC has shortage range, distance of 20cm, which reduces likelihood of unwanted interception hence it is particularly suitable for crowded areas where correlating a signal with its transmitting physical device becomes difficult.)
Compatibility: NFC is compatible with existing passive RFID (13.56 MHz ISO/IEC 18000-3) infrastructures
Energy protocol: NFC requires comparatively low power
Powered device: NFC works with an unpowered device.
NFC devices can be used in contactless payment systems, similar to those currently used in credit cards and electronic ticket smartcards, and it allow mobile payment to replace or supplement these systems.
We believe that NFC will definitely replace the more insecure and outdated RFID cars where its use on smartphone will be limited to contact only applications like payment, access or identification.
Conclusion: And The IoT Winner Is?
It is very likely that the winner of these standards will be one that is available in many of the new devices and phones – otherwise people would not use it. Today every smartphone has Bluetooth and WiFi. However NFC is increasingly being implemented in new phones.
From our experience, a clear Internet of Things winner emerges when you have a very defined use-case. For example, if you’d like to transfer large amounts of files, WiFi is ideal. If you’d like to react on transient passengers, nothing tops Bluetooth. If you want quick, short-range interaction, NFC might be for you. Henceforth, the winning communication protocol really depends on your goals and your clearly defined use-case.