An Overview and the Trends of Wireless Communications for IoT

The wireless communication between the IoT devices and the cloud is what makes the IoT thrive. It’s a middleware system or the middle stack of an IoT project.

When choosing the right wireless technologies for your IoT project, you cannot just pick and choose depending on the cost and range of communication. It is a lot complicated than that.

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Wi-Fi is the most popular and well known for wireless connectivity.  It is used in everywhere from home to office and from store to the airport. On the other hand, Bluetooth is also a popular one which works great in short range, and because it has low latency, it is good for personal area network which includes personal devices such as a speaker, smartphone, headset, and heart rate monitor. The typical ranges for Wi-Fi and Bluetooth are about 50m and 20m, respectively.  They work well in the indoor setting.

If you need a more extended range of wireless service, you need to consider two distinct types of long-range wireless technology.One is the cellular network, which we all familiar with since that is what our cell phones use. Another is the Low Power Wide-Area Network (LPWAN) wireless technologies.

Cellular Network Technologies

The cellular network technologies are mobile network systems which include the GSM, LTE, LTE Cat-M, and provided by mobile telephone providers and the cellular wireless technologies require the use of SIM cards.  The ranges are 2km for LTE, 10-15km for LTE Cat-M, and 30km for the GSM.

We all must charge our cell phones almost every day, and some people need to buy an extra power source to keep their mobile phones alive. 

One of the issues that the GSM network has is that it has a higher energy consumption need. In order to solve this issue, the LTE Cat technology was created to use relatively low energy while it could also perform encryption and made the wireless communication much safer. Moreover, no additional base stations needed since LTE Cat-M1 and Cat-M2 run top of the LTE base stations and have a much longer-range communication ability. However, it requires a dedicated regional frequency channel, and that adds cost to the overall project.  All cellular networks require a contract with a telephone service provider.

LPWAN Technologies

At the end of days, you want all your IoT devices working at less cost. It also means that devices should use minimal energy, so you don’t need to go back to your IoT devices to replace batteries frequently. The maintenance phase of the IoT can be a nightmare as well.  This is where the LPWAN comes to rescue, or at least that’s the goals of it since many efforts already put in its development.  If you implement LPWAN, you may need a gateway to let these IoT devices connect to the Internet

The major players for LPWAN arena are LoRa/LoRaWAN, SigFox, and NB-IoT, and they are competing for large-scale IoT deployment.

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SignFox established in 2009 which is the earliest among these three technologies. It aims for continuous data transmission, and they are heavily been used for electricity meters and smartwatches. The typical range is 24km, and it is possible to create your own private network without relying on service providers.

The LoRa (Long Range) is a patented technology, and LoRa represents the physical layer, and LoRaWAN is the upper layer.  It is great for long range, low power communication, with a typical range of 5-10km.

The NB-IoT (Narrow Band) is the newest and founded in 2016, and it could run in different bandwidth, such as phone radio, old and unused GSM channels and other spaces between LTE channels. It has a typical range of 10km. 

There are just so many factors involved in choosing which wireless technologies to go with since there is no defined line, and the technologies and the service providers are very competitive with each other. You cannot just look at the cost or the range and simply pick one.  It is a lot complicated than that. Down the road, you may need to examine at the maintenance phase of your IoT project closely.

Here are some of the factors you may want to consider:

  1. Power source/battery replacement schedule.

  2. The effects of the harsh outdoor environment on the devices.

  3. The ease of doing the system-wide upgrades and security patches: on the device, on the gateway, and on the cloud (Look for Over-the-Air (OTA) feature on devices).

  4. The possibilities of the technology you used may become obsolete or limited to the availability of service providers.

Trends of Wireless Communication Technologies

Watching the trends of wireless technology development is crucial to your business.  The implementations of LPWAN is going everywhere around the world. According to the GSM Association (GSMA), there are 23 NB-IoT networks and 5 LTE Cat-M1 in the world currently (2018).  China is dominant with NB-IoT technology due to its low latency and service quality, and AT&T and Verizon choose to use LTE-Cat-M networks. T-Mobile focuses on NB-IoT for LPWAN, and currently, it is the first NB-IoT provider in the U.S.

With the rise of 5G technology soon, NB-IoT and LTE-Cat-M must mature quickly to ride the coming wave of 5G, and there are other opportunities like making into a module in other developments. The survival battles in the LPWAN is not yet over.  A partnership could overturn the worse situations.  Both LoRa and Signfox have found that they can be complementary with each other because its range coverages and the degree of integration is quite high while LoRa is an open technology, and together, they do have the competitive edge on areas such as the cost, the ease of implementation, and the wireless ranges. On the other hand, LoRa can leverage the existing LTE networks and works well in a small area like a farm and complement with NB-IoT to bridge these individual areas.  In the end, the trends of wireless technologies may be leaned on a hybrid and complementary technologies instead of playing the elimination games.

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