Why 4G needs help to build the Internet of Things

Telecoms.com periodically invites expert third parties to share their views on the industry’s most pressing issues. In this post, Chris Cave, Director, R&D at InterDigital, looks at how 4G, and even 5G, will need some encouragement in order to accommodate the Internet of Things.

Today’s 4G networks were designed primarily to accommodate and enhance mobile data services, not the Internet of Things. The architectural shift to IP-based infrastructure has enhanced the delivery of high-speed applications like mobile video between users across various connected devices. The arrival of 4G technology essentially delivered a ‘fatter pipe’ and helped to optimize the customer experience for high bandwidth services. The specific nature of 4G technology however means that these same benefits might not necessarily optimize an IoT environment, nor scale to accommodate billions of devices in the same way. The reasons for this lie in the specific nature of 4G communications – how devices are managed and how data is transferred.

Managing waste management for the Internet of Things

With 4G networks, data transmission is accompanied by an exchange of control packets that establish a radio link. This link manages the security and mobility aspects of the device amongst other things. When the data transmissions are large, like they would be for a video file, the proportion of content data to control data overhead is very high, meaning the resulting connection is very efficient.

In an IoT environment however, this same approach faces two major challenges. First, the anticipated transmissions in a lot of IoT applications are quite low. This means that in most cases, the control data forms a significantly larger percentage of the transmission than the content data. This control data or ‘wrapper information’ doesn’t amount to much, maybe as little as a couple hundred bytes of data per transmission. A great many transmissions initiated and shared within an IoT environment however only comprise a hundred bytes of data. A simple temperature sensor reading by a smart meter is a good example. In these instances, the overall proportion of useful to “wrapper” data becomes reversed. When this is multiplied across the billions of connected devices that will make up the IoT, we’re talking about terabytes of wrapper data being created. This combines to create a significant waste management issue for network operators.

5G offers a solution

The fact remains that operators will need more efficient protocols in 5G networks to limit the sharp anticipated increase in wrapper data and handle it effectively. The quantity of this waste data will be significant in its own right and has the potential to negatively impact the transmitting of useful information. This doesn’t just include content data as previously outlined but also power management data (to keep the devices operating efficiently), security or mobility management data. When combined, the size of overall transmission and the vast scale required for the IoT, you soon realize that 4G networks will become bogged down without significant enhancements.

As operators migrate to 5G, there are some network design challenges that must be addressed to meet the demands of the IoT. There are three specific areas where 5G can attack the inefficiencies of 4G for broad-based, low-data IoT transmissions. These can be addressed by asking three key questions.

What mobility requirements are needed?

In a 4G context, the requirement for mobility management is assumed and accounted for – even if it isn’t necessarily required for certain IoT applications. Take for instance, sensors that are attached to the walls of buildings or on factory floors to monitor footfall as part of building automation solutions. In most instances these are fixed points with no need for wider mobility. This means operators can realize significant savings in limiting mobility management data transmissions – the same data that threatens to clog 4G infrastructure.

How can low power requirements be achieved?

Existing mobile broadband networks were not designed to accommodate devices requiring 10 year battery lives.  The network protocol requirements can eat into the long-term battery life targets of certain connected devices. Some of this can be mitigated in certain applications, where time sensitivity isn’t a concern. For example, delay-tolerant data from a low-power, long-battery-life type sensor can be accumulated on the device and transmitted in regular batches with fewer individual connections required. This increases transfer efficiency and preserves some battery life. However, this can only be realized in certain applications, and is really only feasible with applications where preserving battery life is a higher priority than overall connection speed or latency.

What security requirements are truly needed?

Some device connections require higher levels of security than others. A medical device network in a hospital has to be extremely secure because it’s likely transmitting sensitive and private patient health data. In contrast, a network of temperature sensors in a smart city requires less security, because temperature data is neither confidential nor proprietary — it’s merely useful. So from a standards point of view, the network needs to accommodate a wide range of security protocols, from very high (in the case of medical, financial, or sensitive corporate data) to low security (in the case of temperature or weather data) without creating latency, reliability or speed issues as the security level goes up. Security level should be appropriate to the device and application, and the network should allow for a wide range of security levels. Again, the 4G networks were designed with mobile broadband in mind (and therefore a more consistent level of security applied to the network instead of the device), and that may simply not be an appropriate design for a great many IoT use cases. Security should be determined at the device and service level, not the network level.

4G was designed to operate on a human scale, but IHS projects that IoT connected devices could be close to 30 billion in 2019 – with almost 2 billion of those devices operating on 3G and 4G networks. While IoT devices individually may have quite low data rate requirements, it all adds up quickly to data volumes we can scarcely imagine today. It’s a challenge that those driving standards research must rise to.

Christopher Cave is Director R&D at InterDigital Labs, where he leads the development of advanced wireless technologies and Standardization for future wireless systems. Since joining InterDigital in 2001, He has held a variety of engineering and R&D management positions, focusing on the design and development of 3G, 4G, 5G cellular and Wi-Fi systems. As an innovative leader within InterDigital, he has been granted more than 150 patents for his inventions in the areas of wireless technologies and devices.