IoT (Internet Of Things) - What to Choose Home : www.sharetechnote.com
Now let's assume that you got the full unstanding of each of the IoT related technology individually and did a little bit of categorization, you may come up with some daisy chain like diagram as illustrated below.
What is at the center of all these technology ? it's CONFUSION !!! :)
What is confusing you would not be the technical details of each individual technology. What confuse you would about 'how one technology differs from other technologies ?' or 'which technology I have to chose for my application or use model ?'
The simple answer to the question "Which technology do I have to pick for my application or my use model ?" is "It depends on the nature of your application".
I know.. you would not take this as an answer. You would ask for more specific answers.
If you want to get more specific answers, you would have specific answers to a lot of specific questions as listed below. (This list would get extended as learn/observe more from various discussions/forums).
I would not put my comments on each of the questions for now.. just to give you some time for you to think.. (good excuse for my laziness :)).
Q1. What kind of information/data you want to collect with the end node device ?
This is basically asking about the data rate of the end node in your IoT system. Is it collecting a simple data like Temperature, Humidity which takes up only several bytes at a time of transmission. Normally this kind of IoT device should be very low cost. It is less likely to let this kind of device to use relatively expensive network (like cellular network).
Q2. What kind of end node device you will use ?
This is asking 'Are you going to use a simple sensors (like temperature, humidity) ?' or some other devices which requires a relatively large packet transmission/reception or which requires very high level data security.
Q3. What date rate does your end-node device need ?
This would be highly related to Q1. Usually the type of data to be collected and transmitted would determine the necessary data rate, but there might be some exceptions. For example, if you need very sophisticated data security and add a lot of additional portions to the original data to implement the security, the data rate that you would need would get much higher. Another exception can be the case where you want to upgrade/reconfigure your end-node remotely. Of course, this would not happen very often but if you really want to do this, the data rate should be pretty high for the end-node to download necessary firmware and configuration information.
Q4. Does your end node device will both transmit and receive data ? or only transmit the data (no recieve) ?
Most of the IoT application is Uplink centeric (transmission only in terms of end-device) and in some extreme case there are some application that is uplink only. It is understandable for most of IoT application to be Uplink dominant but there would be a lot of restriction if it goes with uplink only. For example, you have a very simple end-device (e.g, a temperature sensor) and transmitted it to a Gateway or Basestation. If the device is uplink only (transmission only), the device can only transmit the data and there is no way to verify whther it successfully reached the destination or not. To verify the successful transmission of the data, there should be some mechanism by which the destination (e.g, Gateway) can send Acknowledge message to the device that has sent the data. To do this, the system should allow downlink (i.e, reception in terms of end-device). Also, if you want to apply any form of data security or remote re-configuration or remote update, you need both uplink and downlink.
Q5. What frequecy you can use ?
Let me ask another question before this .. Are you going to use unlicensed band/frequency (i.e ISM band) or a licensed band / frequency (e.g, Cellular) ? If you decided to use ISM band, it is highly likely to use sub Ghz band (i.e, around 900 Mhz) or around 2.4 Ghz frequency. If you decided to use licensed band, it will be determined by which frequency will be allowed in the area where your IoT system will be installed.
If you selected unlicensed band, you are free to use any of the frequency .. but it is not only you who is free to use the frequency.. there might be a lot of other devices that uses the same frequency which might cause unwanted interference. If you decided to use the licensed frequency, there will be licensing / permission issue.
Q6. How far away a transmitter is from a reciever ?
If the transmitter and reciever is communicating within the range of couple of meters or tens of meters, you can use many of the existing short range communication like Bluetooth, ZigBee etc. However, if it should extend to several km or tens of km, you have to use those technologies that can cover wide range like LPWAN (e.g, LoRa, SigFox etc) or Cellular technology.
Q7. What kind of network your end-node devices will form ?
Q8. How much control you want to have over the whole network ?
Q9. How many end node devices will be playing in the network ?
Q10. Do you need any security for the data being transmitted and received ? At which level, if you need ?
Q11. How do you change/upgrade the firmware/software of the end node/device ?
Q12. What kind of protocol (phy, mac, application layer protocol) do you want to use ?
Q13. How much cost you can afford to ?