Showing posts with label Mesh Technology. Show all posts
Showing posts with label Mesh Technology. Show all posts

Sunday, 27 August 2017

Bluetooth 5 for IoT

Bluetooth 5 (not 5.0 - to simplify marketing messages and communication) was released last year. The main features being 2x Faster, 4x Range (Bluetooth 4 - 50m outdoors, 10m Indoors; Bluetooth 5 - 200m outdoors, 40m indoors) & 8x Data.
I like this above slide by Robin Heydon, Qualcomm from a presentation he gave in CW (Cambridge Wireless) earlier this year. What is highlights is that Bluetooth 5 is Low Energy (LE) like its predecessor 4.0.For anyone interested, a good comparison of 5 vs 4.2 is available here.

In addition, Mesh support is now available for Bluetooth. I assume that this will work with Bluetooth 4.0 onwards but it would probably only make sense from Bluetooth 5 due to support for reasonable range.

The Bluetooth blog has a few posts on Mesh (see here, here and here). I like this simple introductory video below.

This recent article by Geoff Varral on RTT says the following (picture from another source):

Long distance Bluetooth can also be extended with the newly supported mesh protocol.

This brings Bluetooth into direct competition with a number of other radio systems including 802.15,4 based protocols such as Zigbee, LoRa, Wireless-M (for meter reading), Thread and 6 LowPAN (IPV6 over local area networks. 802.11 also has a mesh protocol and long distance ambitions including 802.11ah Wi-Fi in the 900 MHz ISM band. It also moves Bluetooth into the application space targeted by LTE NB IOT and LTE M though with range limitations.

There are some interesting design challenges implied by 5.0. The BLE specification is inherently less resilient to interference than Classic or EDR Bluetooth. This is because the legacy seventy eight X 1 MHz channels within the 20 MHz 2.4 GHz pass band are replaced with thirty nine two MHz channels with three fixed non hopping advertising channels in the middle and edge of the pass band.

These have to withstand high power 20 MHz LTE TDD in Band 40 (below the 2.4 GHz pass band) and high power 20 MHz LTE TDD in band 41 above the pass band (and Band 7 LTE FDD). This includes 26 dBm high power user equipment.

The coexistence of Bluetooth, Wi-Fi and LTE has been intensively studied and worked on for over ten years and is now managed with surprising effectiveness within a smart phone through a combination of optimised analogue and digital filtering (SAW and FBAR filters) and time domain interference mitigation based on a set of  industry standard wireless coexistence protocols.

The introduction of high power Bluetooth however implies that this is no longer just a colocation issue but potentially a close location issue. Even managing Bluetooth to Bluetooth coexistence becomes a non-trivial task when you consider that +20 dBm transmissions will be closely proximate to -20 dBm or whisper mode -30 dBm transmissions and RX sensitivity of -93 dBm, potentially a dynamic range of 120dB. Though Bluetooth is a TDD system this isolation requirement will be challenging and vulnerable to ISI distortion. 

More broadly there is a need to consider how ‘5G Bluetooth’ couples technically and commercially with 5G including 5G IOT

Ericsson has a whitepaper on Bluetooth Mesh Networking. The conclusion of that agrees that Bluetooth may become a relevant player in IoT:

Bluetooth mesh is a scalable, short-range IoT technology that provides flexible and robust performance. The Bluetooth Mesh Profile is an essential addition to the Bluetooth ecosystem that enhances the applicability of Bluetooth technology to a wide range of new IoT use cases. Considering the large Bluetooth footprint, it has the potential to be quickly adopted by the market. 

With proper deployment and configuration of relevant parameters of the protocol stack, Bluetooth mesh is able to support the operation of dense networks with thousands of devices. The building automation use case presented in this white paper shows that Bluetooth mesh can live up to high expectations and provide the necessary robustness and service ratio. Furthermore, the network design of Bluetooth mesh is flexible enough to handle the introduction of managed operations on top of flooding, to further optimize behavior and automate the relay selection process.

Moreover, another Ericsson article says that "smartphones with built-in Bluetooth support can be part of the mesh, may be used to configure devices and act as capillary gateways."

A capillary network is a LAN that uses short-range radio-access technologies to provide groups of devices with wide area connectivity. Capillary networks therefore extend the range of the wide area mobile networks to constraint devices. Figure above illustrates the Bluetooth capillary gateway concept.

Once there are enough smartphones and Bluetooth devices with Bluetooth 5 and Mesh support, It would be interesting to see how developers use it. Would also be interesting to see if it will start encroaching LoRa and Sigfox markets as well.

Friday, 7 July 2017

Wireless Smart Ubiquitous Network (Wi-SUN) - Another IoT Standard

While we have been discussing IoT these last few weeks, here is another one that I came across. This picture above from a recent Rethink research shows that Wi-SUN is going to enjoy more growth than LoRaWAN or Sigfox. Another recent report by Mobile Experts also makes a mention of this IoT technology.

I am sure most of the readers have not heard of Wi-SUN, so what exactly is Wi-SUN technology?

From Rethink Research, The Wi-SUN Alliance was formed in 2011 to form an organization to push adoption of the IEEE 802.15.4g standard, which aimed to improve utility networks using a narrowband wireless technology. The peer-to-peer self-healing mesh has moved from its initial grid focus to encompass smart city applications (especially street lighting), and we spoke to its Chairman, Phil Beecher, to learn more.

Beecher explained that the non-profit Alliance set about defining subsets of the open standards, testing for interoperability, and certifying compatible products, and soon developed both a Field Area Network (FAN) and a Home Area Network (HAN), which allowed it to move into Home Energy Management Systems (HEMS) in Japan – a country that is leading the curve in HEMS deployments and developments.

As can be seen in the picture above:

  • Develops technical specifications of Physical Layer (PHY) and Medium Access Control (MAC) layers, with Network layer as required
  • Develop Interoperability test programs to ensure implementations are interoperable
  • Physical layer specification is based on IEEE802.15.4g/4u/4v
  • MAC layer may use different options depending on the application
  • Profile specifications are categorized based on application types

Picture source for the last three pics, Wi-SUN presentation here.

A new whitepaper from Wi-SUN Alliance provides comparison of Wi-SUN, LoRaWAN and NB-IoT.

A recent presentation by Dr. Simon Dunkley in Cambridge Wireless is embedded below:

Further reading:

Friday, 1 July 2016

EE's vision of Ultra-Reliable Emergency Network

Many of my readers would be aware that UK is probably the first country to have decided to move its emergency services network from an existing TETRA network to a commercial LTE network operated by EE.

While some people have hailed this as a very bold move in the right direction, there is no shortage of critics. Around 300,000 emergency services users will share the same infrastructure used by over 30 million general users.

The following is from an article in Wireless Magazine:

Steve Whatson, deputy director Delivery, Emergency Services Mobile Communications Programme (ESMCP) – the organisation within the UK Home Office procuring ESN – assured delegates that ESN will match the existing dedicated Airwave emergency services communication network in terms of coverage for roads, outdoor hand portable devices and marine coverage. Air to ground (A2G) will extend its reach from 6,000ft to 12,000ft.

Whatson also pointed out that coverage is not one single piece, but will comprise a number of different elements, which all need to mesh into one seamless network run by the ESN Lot 3 Mobile Services (main 4G network) provider – EE.

This includes: EE’s main commercial 4G network; Extended Area Services (hard-to-reach areas of the UK where new passive sites are to be built under a separate contract and then equipped with EE base stations); air-to-ground; London Underground; Crossrail; marine coverage (to 12 nautical miles); and special coverage solutions.

EE is currently rolling out new 4G sites – it will eventually have some 19,500 sites – and is upgrading others with 800MHz spectrum, which propagates over longer distances and is better at penetrating buildings than its other 4G spectrum holdings. Crucially for ESN, it is also switching on a Voice over LTE (VoLTE) capability, starting with the UK’s main cities.
Mission critical networks must be always available and have levels of resilience far in excess of commercial networks. Speaking exclusively to Wireless in early May, Tom Bennett, group director Technology Services, Architecture & Devices at EE, said: ‘We already achieve a very high availability level, but what the Home Office was asking for effectively was about a 0.3% increase against our existing commercial availability levels.

‘Now for every 0.1% increase in availability there is a significant investment because you are at the extreme top end of the curve where it is harder and harder to make a noticeable difference.’

There are very specific requirements for coverage and availability of the ESN network for the UK road system. Bennett says: ‘Mobile is based on a probability of service. No more than 1% of any constabulary’s roads are allowed to be below 75% availability, and on major roads it is 96% availability. A coverage gap in this context is no more than 1km.’

The current Airwave network has approximately 4,000 sites, many with back-up generators on site with fuel for seven days of autonomous running if the main power is cut, along with a range of resilient backhaul solutions.

Bennett says that out of EE’s 18,500 sites it has about the same number of unique coverage sites (ie. no overlapping coverage) – around 4,000. ‘As part of our investment programme, those unique coverage sites will need a significant investment in the causes of unavailability – ie. resilient backhaul and back-up batteries.’

He explains that EE has undertaken a lot of analysis of what causes outages on its network, and it has combined that data with the Home Office’s data on where the natural disasters in the UK have occurred over the past 10 years.

From this, EE is able to make a reasonable assessment of which sites are likely to be out of action due to flooding or other disasters for more than three or four days. ‘For those sites – and it is less than 4,000 – you need generators too, because you may not be able to physically access the sites for some days,’ says Bennett.

For obvious reasons, the unique coverage sites are mostly in rural areas. But as Bennett points out, the majority of cases where the emergency services are involved is where people are – suburban and urban areas.

‘In these areas EE has overlapping coverage from multiple sites to meet the capacity requirements, so if a site goes down, in the majority of cases we have compensation coverage. A device can often see up to five tower sites in London, for example,’ he says.

Having adequate backhaul capacity – and resilient backhaul at that – is vital in any network. Bennett says EE is installing extra backhaul, largely microwave and fibre, but other solutions will also be used including satellite and LTE relay from base station to base station – daisy chaining. On 9 May 2016, EE announced a deal with satellite provider Avanti to provide satellite backhaul in some areas of the UK.

Additional coverage and resilience will be offered by RRVs (rapid response vehicles), which EE already has in its commercial network today, for example, to provide extra capacity in Ascot during the racing season.

‘We would use similar, although not exactly the same technology for disaster recovery and site/service recovery, but with all the backhaul solutions,’ says Bennett. ‘Let’s say we planned some maintenance or upgrade work that involved taking the base station out for a while.

‘We’d talk to the chief inspector before the work commences. If he says, there’s no chance of doing that tonight, we can put the RRV there, and provided we maintain coverage, we can carry out the work. RRVs are a very good tool for doing a lot of things.’

At the British APCO event, Mansoor Hanif, director of Radio Access Networks at EE said it was looking at the possibility of using ‘airmasts’ to provide additional coverage. Meshed small cells, network in a box and repeater solutions are becoming available for these ‘airmasts’, which will provide coverage from balloons, or UAVs – tethered drones with power cables and optical fibre connected to them.

Mansoor Hanif, Director of RAN at EE gave a presentation on this at Critical Communications World 2016 and has also given an interview. Both are embedded below.

Feel free to let me know if you believe this will work or not and why.

Saturday, 16 May 2015

Smart Homes of the Future and Technologies

Saw the above picture recently on Twitter. While its great to see how connected our future homes and even cities would be, it would be interesting to see what technologies are used for connecting these devices.

Cambridge Wireless had a smart homes event last month, there were some interesting presentations that I have detailed below.

The first of these technologies discussed is LoRa. As can be seen, its billed as ultimate long range (10 mile) and low power (10 year battery lifetime) technology. It uses spread-spectrum making it robust to channel noise. Here is the presentation:

The next technology is Zigbee 3.0. According to Zigbee Alliance:

The new standard unifies ZigBee standards found in tens of millions of devices delivering benefits to consumers today. The ZigBee 3.0 standard enables communication and interoperability among devices for home automation, connected lighting, energy efficiency and other markets so more diverse, fully interoperable solutions can be delivered by product developers and service providers. All device types, commands, and functionality defined in current ZigBee PRO-based standards are available to developers in the new standard.

ZigBee 3.0 defines the widest range of device types including home automation, lighting, energy management, smart appliance, security, sensors, and health care monitoring products. It supports both easy-to-use DIY installations as well as professionally installed systems. Based on IEEE 802.15.4, which operates at 2.4 GHz (a frequency available for use around the world), ZigBee 3.0 uses ZigBee PRO networking to enable reliable communication in the smallest, lowest-power devices. Current ZigBee Certified products based on ZigBee Home Automation and ZigBee Light Link are interoperable with ZigBee 3.0. A complete list of standards that have been merged to create ZigBee 3.0 can be seen on the website at

“The ZigBee Alliance has always believed that true interoperability comes from standardization at all levels of the network, especially the application level which most closely touches the user,” said Tobin J. M. Richardson, President and CEO of the ZigBee Alliance. “Lessons learned by Alliance members when taking products to market around the world have allowed us to unify our application standards into a single standard. ZigBee 3.0 will allow product developers to take advantage of ZigBee’s unique features such as mesh networking and Green Power to deliver highly reliable, secure, low-power, low-cost solutions to any market.”

Finally, we have Bluetooth Smart mesh.

CSRmesh enables Bluetooth® low energy devices not only to receive and act upon messages, but also to repeat those messages to surrounding devices thus extending the range of Bluetooth Smart and turning it into a mesh network for the Internet of Things.

While the CW event was not able to discuss all possible technologies (and believe me there are loads of them), there are other popular contenders. Cellular IoT (CIoT) is one if them. I have blogged about the LTE Cat-0 here and 5G here.

A new IEEE Wi-Fi standard 802.11ah using the 900MHz band has been in works and will solve the need of connectivity for a large number of things over long distances. A typical 802.11ah access point could associate more than 8,000 devices within a range of 1 km, making it ideal for areas with a high concentration of things. The Wi-Fi Alliance is committed to getting this standard ratified soon. With this, Wi-Fi has the potential to become a ubiquitous standard for IoT. See also this article by Frank Rayal on this topic.

Finally, there is SIGFOX. According to their website:

SIGFOX uses a UNB (Ultra Narrow Band) based radio technology to connect devices to its global network. The use of UNB is key to providing a scalable, high-capacity network, with very low energy consumption, while maintaining a simple and easy to rollout star-based cell infrastructure.

The network operates in the globally available ISM bands (license-free frequency bands) and co-exists in these frequencies with other radio technologies, but without any risk of collisions or capacity problems. SIGFOX currently uses the most popular European ISM band on 868MHz (as defined by ETSI and CEPT) as well as the 902MHz in the USA (as defined by the FCC), depending on specific regional regulations.

Communication on SIGFOX is secured in many ways, including anti-replay, message scrambling, sequencing, etc. The most important aspect of transmission security is however that only the device vendors understand the actual data exchanged between the device and the IT systems. SIGFOX only acts as a transport channel, pushing the data towards the customer's IT system.

An important advantage provided by the use of the narrow band technology is the flexibility it offers in terms of antenna design. On the network infrastructure end it allows the use of small and simple antennas, but more importantly, it allows devices to use inexpensive and easily customizable antennas.

Sigfox is also working on project Mustang, a three-year effort to build a hybrid satellite/terrestrial IoT (internet of things) network. According to Rethink Research:

The all-French group also contains aerospace firm Airbus, research institute CEA-Leti and engineering business Sysmeca. The idea is to use Sigfox as the terrestrial data link, with satellite backhaul and connections to planes and boats provided by a low-earth orbit (LEO) satellite constellation.
The satellite link could be added to either the end devices or the base station, so that if a device was unable to connect to the terrestrial Sigfox network, it could fall back to the satellite.

While the power requirements for this would be prohibitive for ultra-low power, battery-operated devices, for those with a wired power supply and critical availability requirements (such as smart meters, alarms, oil tankers and rigs) the redundancy would be an asset. These devices may transmit small amounts of data but when they do need to communicate, the signal must be assured.

The Sigfox base station could be fitted with a satellite uplink as a primary uplink as well as a redundancy measure in some scenarios where terrestrial network reach cannot be achieved. With a three-year lifecycle, Mustang’s participants are looking to create a seamless global network, and note that the planned dual-mode terrestrial/satellite terminal will enable switching between the two channels in response to resource availability.

The group says that the development of this terminal modem chipset is a priority, with later optimization of the communication protocols being the next step before an application demonstration using an airplane.

The project adds that the full potential of the IoT can only be achieved by offering affordable mobile communications at a global scale and reach. Key to this is adapting existing networks, according to the group, which explains why Sigfox has been chosen – given that the company stresses the affordability of its system.

Well, there are a lots of options available. We just have to wait and see which ones work in what scenarios.