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The global need in connecting more and more devices that can “talk” to each other and take action based on the data they interchange has resulted in the IoT (Internet of Things) revolution.
This global expansion started with the humble 2G technology and continued with 3G (UMTS), 4G and now the 5G technologies, resulting in faster, higher data rate and secure connection between devices.
However, this leap in data rates also resulted in higher power consumption and greater cost in hardware and network charges.
Many connected devices rely on a secure connection and not necessarily high data rates for their deployment will be a much easier and lower cost if the power required is also lower, hence the advent of low power, low data rate technologies based on a secure global network that is LTE.
LTE CAT1 and LTE CAT4 differ in the amount of uplink and downlink data they offer and their power consumption, as shown in the following two tables:
Table 1: Power consumption at 12V
Mode of Operation |
LTE CAT1 |
LTE CAT4 |
---|---|---|
Registered on the network idle state |
1.2 mA |
12.4 mA |
Registered on the network with socket connected |
1.3 mA |
12.7 mA |
Registered IP address in idle mode |
11.3 mA |
13.1 mA |
IP socket connected and transmitting data |
86.1 mA |
85.1 mA |
Active data call in progress |
130.4 mA |
133.2 mA |
Table 1 shows the power consumption of the two technologies in various states. As it can be seen when data is being transmitted and calls are in progress, there is little difference in power consumption. The real difference is when the devices are in an idle mode where LTE CAT1 uses a 10th of the power LTE Cat4 devices use. As most connected devices spend the great majority of time in idle mode just listening and waiting to send/receive data, the advantages LTE CAT1 offers become apparent.
But there is a trade-off. The table below shows the data rates offered by the two technologies:
Table 2: Data rates
Data rates (Mb/s) |
LTE CAT1 |
LTE CAT4 |
---|---|---|
Downlink |
10 |
150 |
Uplink |
5 |
50 |
Applications
The above tables give a somewhat clear indication of applications the two technologies are suited to.
LTE CAT1 is ideal for low power, low data rate requirements and LTE CAT4 is used primarily for high data rates.
Consequently, LTE CAT4 is used primarily in CCTV, video surveillance, ANPR, Asset tracking, environmental monitoring and so on, where near-permanent connection and high data rate communication is necessary. For applications such as signage, ATMs, metering and car park payments, LTE CAT1 is a more suitable route to take.
Hardware
IoT applications need modems that easily connect to the LTE network and allow communication between remote devices and servers. Wireless manufacturers like Siretta offer reliable LTE CAT1 and LTE CAT4 modems that can be used across the globe for seamless connectivity. Many such modems offer USB or RS232 for serial connections. Additionally, many LTE CAT4 modems offer extra interfaces such as GPIO and ADC that offer greater flexibility to users.
Ease of use
Like any electronic systems, users require hardware and software for wireless deployment. Developing an industrial modem from a wireless module is not easy and can be very time consuming, however as mentioned above industrial modems are freely available that have integrated a wireless module, with SIM reader and interfaces that can be used by any company that has no expertise in hardware development. From a software point of view, a good level of AT command knowledge is needed to initiate and maintain wireless connectivity. Siretta SL500 family of modems are “plug n play” modems that take care of writing any software. Users are given access to a management tool that takes care of all AT command requirement and connect the modems to a server and gives connectivity, data rate and even position information to the user without the need for any software knowledge.
Conclusion
Reliable, seamless and fast connectivity modems are now available for deployment in almost any IoT application and can greatly enhance the performance of many companies all around the world. LTE CAT1 and LTE CAT4 offer a great deal of flexibility in terms of power saving, data rate and interfaces and provide choices to the user that was not possible until now.