The IEEE 802.15.4 standard has become a cornerstone of low power wireless communications, both consumer and commercial, through market adoption by the Zigbee and the Thread standards groups. Both the Zigbee and Thread protocols support wireless mesh networking, with Zigbee being a proprietary network and Thread being based on the internet-protocol version 6 (IPv6).
The IEEE 802.15.4 standard has been designed specifically for interoperability with interferers, both through the detection of the presence of another IEEE 802.15.4 carrier, or from another in-band protocol such as Wi-Fi. The interference-avoidance mechanism uses the CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) channel access mechanism. With this mechanism, a transmitting device first checks whether the channel is clear of interferers, before attempting transmission. If it observes that the channel is clear, it will start transmitting. If not, it will retry the entire procedure after a random time interval within a programmable limit.
This approach works well when all nodes can "hear" each other, which is a rare case in large networks. If a node is not capable of discovering what is happening beyond its receiver range, then its transmission can lead to hidden-node collision. This phenomena is known as the hidden node (or hidden terminal), problem.
Increasing the transmit power of nodes within a dense network does not necessarily solve the problem, as it increases the probability of causing hidden-node collisions in another part of a mesh network. Moreover, the transmit power of the IEEE 802.15.4 protocol is limited to just 10mW in most of the world outside of North America.
It has become evident through real-world deployments from product manufacturers that the IEEE 802.15.4 protocol struggles to cope in the presence of interferes, due to the hidden interferers.
Previous attempts to solve the problem include changing the modes of interferer detection, increasing the number of retries and moving to an additional retry delay after not having received an acknowledgement after transmission. This project aims to measure the effect of increasing receiver sensitivity as a means of mitigating against the hidden node problem.
An innovative new device for building management solutions; built using internet protocol (IPV6) from end-to-end, ensuring security, interoperability and high extensibility. The device will use data models and standards defined by the open connectivity foundation (OCF), ensuring that vendor lock in via closed protocols will become a thing of the past.
Currently, Building Management Systems (BMS) are predominantly plant-room based hardware controls that necessitate manual interaction. This means that when scheduled or unscheduled maintenance is required, an engineer has to be physically present to fix the problem.
As during the pandemic, when a building is unused for a period of time - normal services operation leads to unnecessary levels of energy consumption. Combined with this primary inefficiency, any overall deterioration in building performance goes unnoticed. This leads to further negative impacts on both energy usage, environmental impact and the bottom line.
Pulse Systems have designed an innovative new product that makes these obstacles a thing of the past. With this technology, BMS are simply uploaded to the Cloud -- meaning that they can be operated remotely. This gives building managers the power to see everything going on in their building, giving them control over everything from hardware malfunctions to a forgotten light switch. Cloud BMS removes the need for many physical maintenance visits, which in the context of a post-pandemic society can be difficult, dangerous and financially detrimental.
The device will be built using internet protocol (IPV6) from end-to-end, with data models and standards defined by the Open Connectivity Foundation, ensuring the highest level of interoperability and security for our clients. In addition, the change from closed to open protocols translates to improved transparency and agency -- the customer can choose to share their data but this is completely at their discretion. Functions for this capability include being able to see exactly how and where energy is being wasted and share that with the users of the building or energy providers. This provides obvious financial benefits and promotes sustainability.
In the current climate, environmental consciousness is key. Pulse strives for carbon neutrality in its own business, and our product encourages and enables our clients to reach for this goal. With a product that allows the energy performance of a building to be accessed and altered from anywhere, clients are empowered to make the most responsible energy choices for them and for their community.
In short, all of this translates to a product that has low installation costs, low maintenance and update costs and that will integrate well with both current and future systems.
The aim of the project is to develop a prototype radio device for use in smart meters and other energy management systems, designed specifically to overcome the range against power consumption problem for low-power wireless protocols, thus allowing whole-house coverage.
The aim of the project is to develop a prototype radio device for use in smart meters and other energy management systems, designed specifically to overcome the range against power consumption problem for low-power wireless protocols, thus allowing whole-house coverage.