If it seems to you that Bluetooth and WiFi, the two most widely used forms of wireless connectivity, have been around for a very long time, well, it’s pretty much true. Back in 1994, Ericsson invented Bluetooth and the Bluetooth Special Interest Group (SIG) then adopted enhancements in the form of spec 1.0 (1999), 1.2 (2003), 3.0 (2008), 3,0 High Speed (2009), 4.0 (2010), 4.1 (2013) and 4.2 (2014).
Similarly, in 1999 IEEE released 802.11a and 802.11b (802 is the IEEE prefix used for any protocol or amendment that entails area networking), which for many years were the standard for WiFi networks. In the 19 years since we began to see the first 802.11b wireless routers and laptops four more mainstream WiFi standards have been proffered: 802.11g, 802.11n, 802.11ac and 802.11ad. 802.11ac (2013) added very high throughput – multi-station WLAN throughput of at the least 1 Gbps and an individual link throughput of at the least 500 Mbps. The IEEE 802.11ad standard, aimed at very high data rate, very short range communications, added a "fast session transfer" feature, enabling wireless devices to seamlessly make transition from the legacy 2.4 GHz and 5 GHz bands to the 60 GHz frequency band.
Today, Bluetooth, WiFi and champions of other wireless protocols (ZigBee, LoRa, NB-IoT, for example) are planning enhancements for their respective technologies focused squarely on increasing Internet of Things (IoT) functionality. All as these competing groups hope to become the force behind wirelessly connecting billions of IoT devices. They know the WLAN environment is evolving and is no longer one where devices are merely looking for access to Internet service. This creates opportunities to deliver new services, and the standards-bearers recognize with the emergence of the IoT their wireless protocols need to be improved with regard to efficiency, speed, range, and the ability to better project and describe these new services.
Let’s take a look at what’s being developed.
WiFi HaLow (pronounced “halo” ) is a new type of WiFi and an extension of the upcoming IEEE 802.11ah standard meant to work on low-power devices, promising to deliver a 10x power reduction compared to state-of-the-art 802.11 OFDM transceivers (in this sense HaLow can be thought of as WiFi's answer to Bluetooth). It is expected to travel farther and do a better job of traveling through walls. The first WiFi specification to operate in frequency bands below one gigahertz (it’s at 900 MHz, a much lower frequency than the existing 2.4 GHz and 5 GHz WiFi technologies), HaLow will have a range of nearly twice that of other WiFi variants (it is designed to reach up to 1 kilometer, or 3,300 ft. On the flip side HaLow isn't going to be as good at quickly transferring data because the trade-off is that speed greatly decreases the longer the distance from the transmitter; 802.11ah devices will be able to only transmit data at scalable rates from 150 Kbps to about 2 Mbps; in short this isn't WiFi for browsing the web, it's for transferring small bits of data on infrequent occasions so it should not require a great deal of power. HaLow would be applicable in smart building applications, like smart lighting, smart HVAC and smart security systems.
IEEE Standards Board approval of 802.11ah is expected in September, 2016 and the Wi-Fi Alliance intends to begin certifying HaLow products sometime in 2018 IEEE 802.11aq is being developed to provide a cellular-like automatic network-discovery experience. This 802.11 amendment will provide mechanisms that assist in pre-association discovery of services and enable delivery of information that describes them. These records about services will be made available ahead of association by stations operating on IEEE 802.11 wireless networks.
For environments where mobile users are constantly entering and leaving the coverage area IEEE 802.11ai will provide a fast initial link setup function that would enable a wireless LAN client to achieve a secure link setup within 100msec.
802.11ax will work in roughly the same fashion as 802.11ac — just with massively increased throughput. By way of review 802.11ac allows for up to four different spatial streams (MIMO) and 802.11ax will increase the spectral efficiency (and as a result throughput) of each stream. Higher efficiency is necessary in dense deployments such as stadiums, shopping malls, and subways where you have a lot of people accessing the WiFi system. It will use bands between 1 and 6 GHZ, support 5G cellular in terms of density and rate and is slated (for now) for 2018 standards approval.
Bluetooth has been adopted by countless developers and manufacturers and yet the Bluetooth Special Interest Group (SIG) is planning significant new enhancements for the technology focused squarely on increasing its Internet of Things (IoT) functionality. Key updates include longer range, higher speeds and mesh networking. Bluetooth advancements will be coming later this year to further energize fast-growing industries such as smart home, industrial automation, location-based services and smart infrastructure. Most notably, Bluetooth is aiming to increase the range of Bluetooth 4.0+ (aka Bluetooth Smart/ Bluetooth Low Energy [BLE]) by a factor of four. That means a fitness band will not lose its connection to your phone as you move around the house.
A 100% increase in speed, without increasing energy consumption, will enable faster data transfers in critical applications, such as medical devices, increasing responsiveness and lowering latency. And mesh networking will enable Bluetooth devices to connect together in networks that can cover an entire building or home, opening up home and industrial automation applications.
In a Bluetooth Mesh network, data will "hop" from one device to another until the message reaches its final destination. The objective of Bluetooth Mesh networking is to have it backward compatible to Bluetooth 4.0. Instead of pairing each individual Bluetooth device to your smartphone, all your Bluetooth devices will connect to each other. Together, this collection of devices would form a smart "Mesh" network covering your whole home. The Mesh networking protocol will ride over BLE.
ZigBee 3.0, ratified last December, builds on and unifies ZigBee standards already onboard hundreds of millions of shipped devices. ZigBee 3.0 is based on IEEE 802.15.4, which operates at 2.4 GHz (a frequency available for use around the world) and uses ZigBee PRO networking to enable reliable communication with small, low-power devices. The ZigBee 3.0 standard enables communication and interoperability among devices for smart homes, connected lighting, and other markets. The initial release of ZigBee 3.0 includes ZigBee Home Automation, ZigBee Light Link, ZigBee Building Automation, ZigBee Retail Services, ZigBee Health Care, and ZigBee Telecommunication services. The LoRa Alliance is an association of members whose mission is to standardize Low Power Wide Area Networks (LPWAN) being deployed around the world. The LoRaWAN specification is intended for wireless battery operated IoT devices in regional, national or global networks.
LoRa, which derives its name from its ability to enable “long-range” communications, is based on the chirp-spread-spectrum modulation format (CMSS) with robust interference suppression capabilities and the same low-power characteristics of frequency-shift-keying (FSK) modulation (but LoRa significantly increases its communication range). Chirp spread spectrum has been used in military and space communication for decades due to the long communication distances that can be achieved. A single LoRa gateway or base station can cover entire cities or hundreds of square kilometers.
LoRaWAN network architecture is typically laid out in a star topology in which gateways act as a bridge relaying messages between end-devices and a central network server in the back end. The gateways are connected to the network server via standard IP connections while end-devices use single-hop wireless communication to one or many gateways. All end-point communication is generally bi-directional, but also supports operation such as multicast enabling software upgrades over the air or other mass distribution messages to reduce the on air communication time.
Communication between LoRaWAN end-devices and gateways is spread out on different frequency channels and data rates. The selection of the data rate is a trade-off between communication range and message duration. Due to spread spectrum technology, communications with different data rates do not interfere with each other and create a set of "virtual" channels increasing the capacity of the gateway. LoRaWAN data rates range from 0.3 kbps to 50 kbps. To maximize both battery life of the end-devices and overall network capacity, the LoRaWAN network server is managing the data rate and RF output for each end-device individually by means of an adaptive data rate (ADR) scheme. LoRa is competing against other proprietary technologies such as Ingenu (a dedicated M2M technology), Sigfox (a subscription-based low-power, wide-area (LPWA) communications network currently operating in 18 countries and with over seven million registered devices) and cellular technologies like Narrow-Band IOT (NB-IoT). Being standardized by the 3GPP standards body NB-IoT is specially designed for the Internet of Things, hence its name. The special focus of this standard are: indoor coverage, low cost, long battery life and a large number of devices. This technology can be deployed in GSM and LTE, utilizing resource blocks within a normal LTE carrier, or “standalone” for deployments in dedicated spectrum. The NB-IoT downlink will use a 180 kilohertz (kHz) Orthogonal Frequency-Division Multiple Access with twelve 15kHz subcarriers; NB-IoT technologies will have an uplink ‘single tone transmission’, which is key to optimized battery life and deep in-building coverage. It will have an uplink option of ‘multi tone transmission’ to enable higher data rates for good coverage.