The IoT Architecture
When we first consider what the IoT architecture looks as if it is a good starting point to consider the technology enablers on which IoT is built. The technologies required for IoT are:

- Sensor Technology
- RFID Technology
- Wireless communication
- Energy harvesting technology
- Cloud computing
- IP v6

The technologies listed above are just a few of the common tools and methods being deployed in existing IoT applications and systems. For example, RFID labels are widely used in transport and logistics, as they are very easy to apply and handle. Similarly, Barcodes and QR codes are widely adopted within retail so it makes sense to continue to utilize them as they are easily applied and read using a variety of hardware.

The choices of network connectivity typically will come down to Wi-Fi, as it is ubiquitous, low cost, high throughput and easily installed and maintained. However not all devices will be able to support 802.11 Wi-Fi due to their processing limitations and bandwidth therefore there is the alternative Zigbee, which was developed for device communications over PAN (Personal Area Networks). Additionally Zigbee is low cost and
has very long battery life and can be deployed and operated worldwide. Zigbee is perfectly suited for PAN and mesh-networks as it is also secure and flexible enough to support many network topologies.

However, connectivity may not always be as simple as locating sensors within your house or office. What if the object you are tracking moves about out with your Wi-Fi range? This is one of the issues that have to be addressed, as there will not always be internet connectivity where you might need it, for example, the connectivity may be unavailable, intermittent or unpredictable.

TCP/IP is the protocol of internet data networking and communications. It has been around a long time and is perfect for long distance transmission over unreliable networks such as the internet. Indeed much of TCP/IP value is the components that enable it to handle lost packets reorder packets and elegantly handle variable latency, packet loss and jitter. However, all that functionality comes at a cost and the TCP/IP stack can be overkill for many IoT applications. TCP/IP requires a three-way handshake to establish a connection, a session, between source and destination but sometimes in some environments that simply is not possible. Therefore, we still need to find an alternative to TCP/IP that will support connectionless communication to cater for scenarios where there is no path between the source and the destination.

For example, earlier we considered a farm application for IoT that tracked animals as they grazed. However, what if the grazing land stretched for miles in either direction, it might not be possible to be in constant communication with each beast, but do you need to be?
Perhaps they only need to communicate their presence when they come into range of a base station. In that case, we need a communication standard other than TCP perhaps a connectionless standard, which would allow data to be stored temporarily and then transferred to a control unit once contact is established with a base station.