It is hard to believe that the word “Wi-Fi” was added to Merriam-Webster’s Dictionary less than 10 years ago. Since then, the technology has made tremendous strides, starting with 802.11b, 802.11bg and advancing to 802.11abgn. Out of all the wireless technology options that exist today, expect Wi-Fi to play a significant role in the Internet of Things (IoT) evolution. The reason: it connects directly with IP networks, is well understood and ubiquitous, and provides tremendous flexibility to serve many use cases.
802.11 has morphed into several variants that can be tailored for specific application needs. To help frame this discussion, we are going to focus on three major attributes where standards have evolved to address specific market needs: high performance networks, wireless sensor networks, and peer-to-peer networks. Here’s a look at each and how they are evolving with the IoT revolution.
High Performance Networks
These networks host the applications that are driving the need for higher speed. 802.11n broke the 100Mbps barrier when smartphones and tablets first shipped. Then this year we saw a proliferation of 802.11ac technology that opened the door for gigabit speed.
802.11ac added higher data rates and more efficiency with operation in 5GHz (which is generally a cleaner and less crowded spectrum than 2.4GHz) and optimized performance of multimedia traffic. Devices can transmit and go to sleep faster to improve battery performance. Building on that, recently launched smartphones and tablets enable 802.11ac technology that optimizes the mobile experience. Devices that are plugged-in or have larger battery capacity can take advantage of 802.11n 2x2 and have two mounted transceivers (2 Tx/2 Rx) for even higher performance. Laptops and set-top-boxes are well suited for 802.11ac 2x2 devices.
In addition to 802.11ac, the Wi-Fi Alliance recently ratified 802.11ad (also known as WiGig). WiGig is responsible for bringing Gigabit speed to Wi-Fi. This allows data transfer to occur at up to an astounding 7Gbps. Unlike 802.11ac, 802.11ad operates at 60GHz. Due to its high frequency, it has a very short range but enables high throughput. This makes it ideal for transmitting video from handhelds to large screens instantly (think of a best-in-class experience in your very own living room) or to enable wireless docking. Because 802.11ad is a different frequency than 802.11ac/11n, they can both be embedded in a single chip. 802.11ad also lays the groundwork for transmitting an entire HD movie in just minutes versus hours. This is of great interest to the home entertainment, gaming, automotive, and medical markets.
Wireless Sensor Networks
Wireless Sensor Network (WSN) contains tiny sensor nodes transmitting various low data rates. Typically, these are battery operated and send various signals at very low data rates over the IP network so that their status can be monitored remotely anywhere around in the world. The key requirement for WSN is low power nodes as they operate on a very small battery for years. Also, longer range is desired so that in a given area, you can operate with a smaller number of communications nodes. 802.11b and 802.11g are desired as they provide longer range and battery power. There are 802.11 chipsets designed to optimize lower current consumptions but also support very low throughput such as 1Mbps.
802.11 specifications are evolving to allow further optimization for WSN applications. 802.11ah is being defined to enable Wi-Fi over 900Mhz frequency. Lower frequency spectrum allows products to communicate over a longer range. Currently, Wi-Fi can be achieved on 2.4, 5 and 60 GHz. By enabling Wi-Fi over 900 MHz, a very long-range communications is established that reduces the need for the total number of nodes in the network, thus reducing cost. As it stands now, many WSN networks are operating at 900 MHz, but they are proprietary communications protocols. Enabling Wi-Fi in this band would open a huge opportunity for devices to be connected to IP networks in a more expedited way.
Peer-to-Peer Networks
Current 802.11 specifications support Wi-Fi direct, allowing Wi-Fi devices to talk to each other without an access point. This feature is widely used in many consumer applications, such as printers. One other key peer-to-peer network application is car-to-car communications. 802.11p is an approved amendment to the IEEE 802.11 standard to add wireless access in vehicular environments (WAVE), a vehicular communication system. Dedicated Short-Range Communications (DSRC) and WAVE protocols of 802.11p were developed specifically for the Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) communications protocol. It is optimized to send safety and control messages, including collision avoidance. This protocol was designed for low latency and fast connect-disconnect as they can gauge vehicles’ proximity to one other. The standard was ratified many years ago, but there was not a strong push to commercialize this protocol until recently.
In August 2014, the U.S. Department of Transportation released advanced notice on new standards that would mandate V2V communications in newer vehicles to enable crash-warning systems. There has not been a well- defined timeline for this mandate, but 802.11p/DSRC trials have been on-going for a several years by auto manufacturers and 802.11p seems to deliver the promise of making V2V reality in coming years.
With the plethora of new applications in many of the new verticals with 802.11 technology, we expect a huge increase in connected devices including appliances, machines, equipment, automotive and people and hence driving the Internet of Things (IoT) revolution. This presents enormous opportunity for all members in the ecosystem from hardware, software, and system solution providers.
About Murata
Murata is the world leader in designing 802.11 variant modules. The company has a unique advantage to commercialize the many Wi-Fi variants that are required to support the need of these major vertical markets described above. Murata already serves many of these markets now with a broad portfolio of modules including 802.11bgn, 802.11abgn, 802.11ac, 802.11ac 2x2, embedded Wi-Fi (with built-in stack), 802.11ad/WiGig and 802.11p. These modules are available in consumer, industrial and automotive grade to suite specific market needs.