At one time we had to think of Internet connectivity only from the perspective of desktop and laptop computers. Then it went on to personal digital assistants (PDAs) and other handhelds, followed by mobile phones, industrial instruments and machinery. Now it’s even existent in printers, televisions and cars, and the future sees it in cameras, microwaves and washing machines too!
What is the best possible way to make Internet-capable embedded systems for these innumerable devices? Do we need special processors? What kind of operating systems? How do you make the systems smaller, cooler and faster? How can we make them interoperable and secure? Which are the best interfaces and protocols?
As more and more people try to find the best answers to these questions, pledging their knowledge and skills to the realisation of the ‘Internet of Things’—a vision of connecting ambient objects and devices to monitor and control our environment, we see lots of brainwaves and lots of quizzical looks too. Of course, with so many developments around the world it could sometimes get difficult to keep track o where we are heading. In this article, we plan to ease some of those creased brows with an express overview of recent trends concerning embedded Internet systems.
Inside all things, small and big
“The area of networked embedded applications, termed as ‘deeply embedded systems,’ deals with embedded devices connected over a network. It has a multitude of sub areas such as home automation, industrial networks, vehicular automation and wireless sensor networks,” begins Prof. K.R. Anupama, associate professor & head of the department-electrical & electronics engineering, electronics & instrumentation engineering, BITS, Pilani, K.K. Birla Goa Campus. Intel terms this as the fourth phase in the evolution of the Internet; the first being the connection of mainframes, the second being e-commerce and e-mail revolution, and the third being social networking. With embedded systems getting more advanced and so many devices waiting to be connected to the Internet, there is no end to the possibilities.
“Saying that a BMW M5 would support Facebook and Twitter integration is an indication that we are getting there,” quips Sridharan Mani, director and CEO, American Megatrends India. M2M World News Insight says that in 2010 around 22 million connected consumer devices were shipped with the number likely to double in 2011. Forecasts indicate that by 2015 around 270 million consumer devices with embedded connectivity would be shipped.
If you set aside typical computers and look at the embedded Internet market today, it is very evident that mobile telephony is the apple of the industry’s eye. “Embedded devices catering to the mobile segment, like iPhones or Android phones, are most equipped today owing to the widespread adoption of 3G, 4G LTE and other high-speed data networks. With the advent of latest tablet PCs and e-book readers with Internet connectivity using 3G modems, or with Wi-Fi, the mobile telephony segment has the most widespread embedded capability today. This trend is most likely to increase in the future with mobile Internet overtaking desktop Internet, just like how mobiles now outnumber landlines,” explains Mani.
Other consumer electronic (CE) devices such as televisions are also beginning to get connected. Even the averagely-priced models of modern televisions have an ethernet port to access content from the Internet. Similarly, brands like Canon and Samsung also have digital cameras that can connect to the Internet using a Wi-Fi connection, and directly upload pictures to popular photo-sharing websites. There are also video cameras that can stream movies live over the Internet. These are still a preserve of the elite though.
Anup Sable, senior vice president-automotive and engineering, KPIT Cummins feels that household CE devices like kitchenettes, washing machines and ovens will also have connectivity as a key feature in the near future.
Why would you want to have an oven or washing machine that connects to the Internet? Imagine the convenience of being able to ‘connect’ to your oven and set it to start cooking just before you leave from office.Hot dinner ready in a jiffy! If something goes wrong with your washing machine the service person would be able to ‘connect’ to it from his office, diagnose the problem, and perhaps even set it right from there; or at least come equipped with the parts needed to fix the problem during his first visit itself.
Cars are also getting more Internet-savvy. Although automobiles have long been able to connect to networks—mainly GPS applications—more generalised Internet capabilities are also being talked about now. A number of Internet radios and in-car modems are being introduced in the market; and the latest BMW supports an iPhone application for Facebook and Twitter integration.
Industrial automation and home automation systems are also a huge market for the embedded Internet industry. Internet-capable measurement instruments as well as machinery are used extensively today—to feed data live to centralised IT solutions, for monitoring and adjusting processes as well as for decision-making. Likewise, energy management systems, intelligent lighting solutions and premise security applications utilise a lot of Internet-capable devices. Some CCTV camera models, for example, come with Internet capability, and the output of these can be viewed from any remote PC or mobile phone.
Prof. Anupama remarks, “The trend will move towards military and industrial applications where embedded devices will begin to meet more and more real-time demands. After a certain period of advancement, the trend will move more towards implementing the embedded devices for day-to-day needs like traffic monitoring, precision agriculture, water resources management, resource mining, etc.”
Basic components—not too different
Like all computers, embedded systems also comprise processors, operating systems and software stacks—just that they use small and barebones versions of everything, so that the footprint in terms of size, power, etc, is small enough to be embedded into another device. To add Internet-capability, the system would also have to include a modem and the relevant software stacks to establish connection. Depending on the application, other software or hardware components might be added. For example, a mobile phone might also include e-mail clients, browsers, special purpose players, etc.
As far as the Internet capability goes, again the components draw a parallel with regular computers—only the footprint matters. “There would be nothing special in terms of hardware. Most of the devices use a Wi-Fi chip and/or a 3G modem, which would be connected to the host processor. Thanks to the open source revolution, all the necessary software stacks to establish a Transmission Control Protocol/Internet Protocol (TCP/IP) connection with driver support are available readily. It is a lot easier and cheaper to design a ‘connected’ system in today’s embedded world,” says Mani.
Prof. Anupama adds, “The technology used to access the Internet could also be GPRS, Bluetooth, ZigBee, WiMAX, etc. It is again specific to the application. But generally, embedded systems with Internet communication will employ hardware accelerators to meet the demands of data transfers and the time-criticality of the data. Since the processing required for Internet-equipped embedded devices is more than the standalone devices, the processors used in these devices are also advanced.”
Protocols, old and new
Asked about the networking protocols preferred by embedded Internet systems, Mani says, “Similar ones as used in computers. TCP/IP, IPv4, IPv6, SIP, etc, are the protocols used for embedded applications as well. The only difference is that these stacks are optimised to fit on small footprint devices.”
Sable adds, “At the core level, TCP/IP is predominantly used. At the application level, HTTP, FTP, RTP, RTSP and SSL are some of the widely-used protocols.”
As mentioned, IP is one of the most commonly-used protocols, even for embedded systems. IPv4, the dominant protocol of the day, uses a four-byte addressing system that can give unique addresses to 232 systems. However, these addresses are fast running out, and will certainly not be sufficient when we move closer to the Internet of Things. Hence a newer version called IPv6 that uses a 16-byte addressing system has been released and has also started being deployed. It is more likely that Internet-capable embedded systems in the future will be using IPv6—the trend is likely to begin with electrical appliances.
This brings us to the question of whether even a 16-byte address would be enough if every oven, fridge, washing machine and even perhaps bicycles and radios were to be Internet-capable. In an article on the subject, Clive Max-well, writes: “According to calculations and estimations performed by the folks at the University of Hawaii (who obviously have far too much time on their hands), if we account for all of the beaches around the world, together they contain around 7.5×1018 grains of sand. Thus, the addressing space of IPv6 is sufficient to give each grain of sand its own unique IP address—and to do this for approximately 5×1019 Earth-like worlds—so I don’t think we’re going to run out of IPv6 addresses in the foreseeable future.”
Apart from this, there is also a class of low-power wireless personal area network (LoWPAN) protocols. In such networks, the nodes are very small and may be powered by an 8-bit, 16-bit or 32-bit microcontroller with 64kB or more of Flash memory. The most commonly used underlying transport protocol is defined by the IEEE 802.15. standard, and the packets of data are only 127 bytes in size.
Above this there is wireless stack, and then the set of applications to be run on the node. This is the kind of network that is normally used in home or industrial automation for the nodes to communicate with each other. Some of the technologies in this category include ZigBee, Z-Wave, EnOcean and SNAP. SNAP is the technology that has been chosen by Google for its [email protected] project—a smart home-like effort.
So, we have standard Internet-level networks like TCP/IP on one side, and LoWPANs on the other. However, in order to move closer to the Internet of Things, we need all the nodes in the LoWPAN to also be Internet-capable and have their own Internet address—so that we can access and control these nodes from anywhere in the world using any device connected to the Internet (like a computer or a mobile phone).
This problem is not as easy as it sounds, because the size of the packets in the standard network can range from 1500 to 9000+ bytes, while the packets in the LoWPAN are only 127 bytes in size. LoWPANs also have lower data bandwidths and low power. As a result of some industry efforts, we now have an open standard called 6LoWPAN (where the ‘6’ stands for IPv6), which describes how to take a large packet from a standard Internet-level network and strip it down by removing a lot of high-level complexity and redundancy, to make it small enough for handling by the LoWPAN.
The 6LoWPAN specifiation also describes how to take small LoWPAN packets and reformat them for passing on to a higher-level network. So, it is expected that we will soon see 6LoWPAN wireless protocol stacks. However, some challenges related to creating and deploying applications based on this standard are to be ironed out before this happens.
Keeping away the snoopers
When we speak of embedded Internet systems—be it in a mobile phone or in a television, security is a key issue. Especially, when you think about the context of an Internet of Things, where all ambient objects have computers embedded in them, and will be connected to the Internet and to other objects around them including your own computer, the points of ‘break-in’ also increase. In the worst case, your microwave or washing machine could serve as the unguarded back entrance for somebody to break into your computer and steal all your confidential data. Hence protection from malicious access is an important aspect of designing and developing embedded Internet systems.
Sable shares an example, “With the power of embedded devices in the car infotainment space, hackers can take control over the system and remotely take control of your car. In some cases, the compromise of personal information can cause unwanted distress as well. The current-day embedded systems are a mixed bag when it comes to security; some handle it well, others don’t.”
There are such many situations where the security challenge deepens in the case of embedded systems. For example, where an Internet-enabled device needs to connect to an untrusted foreign network, say a wireless access point at an airport. The cryptographic algorithms should be powerful enough to allow sufficient security, while still having low power consumption and capable of running on systems with resource restrictions. “There are other scenarios where the security weakness could stem from the basic Internet protocol itself (say like HyperText Transfer Protocol (HTTP) streaming from a Web service in which a firewall cannot filter sensitive transmission) and needs additional layers of security,” adds Mani.
While these sound similar to the security issues faced by personal computers and other larger systems, the challenge transforms into a catch-22 in the case of embedded systems—the security algorithms need to be very comprehensive because of the real-time nature of embedded system operations; yet they need to be small and low-power.
Prof. Anupama explains, “Embedded devices are low-power, small-sized and energy-hungry devices. The security algorithms available in the market are processor hungry, which contradicts the basic axioms of the embedded devices. The current encryption and decryption algorithms are complex and require high processing power, and hence cannot be implemented easily on the low processing capability embedded devices. Making the embedded devices complex is not a solution as this will only increase the price of the devices—easy-to-implement encryption and decryption algorithms need to be developed.”
To overcome these challenges and incorporate the required levels of security consistent analysis and audits throughout the product engineering lifecycle would be required. It would require the setting up of a holistic security mechanism, working from the design/architecture upwards.
A path-breaking story titled ‘The Embedded Internet’ was published in the Wired magazine in 1996. The article introduced a miraculous technology that could change the face of the Internet, and the world—“Tiny crash-proof computers that are embedded or hardwired within everyday products and dedicated to the performance of specific tasks or groups of tasks.” No prizes for guessing that the revolutionary technology discussed therein is nothing but the humble embedded system that is so ubiquitous today.
Read the article at http://www.wired.com/wired/archive/4.10/es_embedded_pr.html to realise how far we have come in the past decade! What the author called exciting new stuff then is commonplace now; things he called dreams are a reality today; but the ultimate goal of an “Internet of Things” remains to be realised!
Security is just one of the many challenges in the making of embedded Internet systems. Some of the other issues include:
Power management. Current embedded devices employ high-end peripherals and heavy software stacks leading to the increased consumption of power, and consequent reduction in battery life. Employing peripherals that support low power modes is one of the tried and tested mechanisms for overcoming this issue, but there is a lot of scope for improvement in this area. “Power management also requires focus on the system architecture that includes hardware as well as software,” says Sable.
Full usage of channel. Most of the embedded devices available are capable of supporting communication over fast ethernet or even gigabit ethernet. “Though the communication is over the ethernet, they are not capable of using the channel to the full extent. On an average, most of the embedded systems are capable of transferring only a few bytes of data while meeting the energy constraint of the applications in parallel,” says Prof. Anupama. Hence, in the future, engineers will have to work out how to enable the embedded Internet devices to make full use of the channel, without considerable increase in power consumption.
Predictability of delays. Current Internet technologies do not feature predictable delays in data delivery. Most Internet-based embedded applications are real-time, and hence predictable time delay is a basic requirement. Although modifications such as the real-time Ethernet exist, they are yet to be implemented in all embedded devices.
Need for better middleware. The multitude of embedded devices and the variations in hardware and software configurations of these devices require the use of middleware—an area still under development.
Fortunately, there is loads of motivation to solve these and other issues that remain in the embedded Internet system space, since the demand for such systems is growing phenomenally and expected to grow even faster. With the projected growth of cloud computing, e-commerce and other applications in the near-future, as well as the enthusiasm to implement the Internet of Things, the demand for Internet-capable embedded systems is only likely to see an upwards trend.
“Embedded computing is undergoing a transformation. Breakthroughs in computing per watt, in parallel with advances in wired and wireless broadband connectivity, will enable the development of billions of new intelligent embedded devices. We foresee thousands of devices embedded in civil infrastructure (buildings, bridges, water ways, highways and protected regions) to monitor structural health and detect crucial events. Eventually, such devices might be tiny enough to pass through bodily systems or be usable in large enough numbers to instrument major air or water flows! In short, the demand for such systems is expected to grow rapidly,” signs off Prof. Anupama.
The author is a technically-qualified freelance writer, editor and hands-on mom based in Chennai