Recurrent question where I usually see the wrong option taken by industrials: do I need to implement my own private network for m LPWA network ? In many case the wrong choice has been made due to a lack of understanding of network total cost of ownership. For sure I heard element about MY DATA privacy, but honestly, all the companies are putting added value data into the Cloud, so don’t tell me you unknown machine temperature is a sensitive data ?!? That said, let’s back to the true question : when does it make sense to create your own private network ?
What is a private LPWA network infrastructure ?
It is important to understand what are the minimal components required for a LPWA network infrastructure :
- First of all the gateways (antennas). Even if for your POC using one antenna was a good idea, the reality is you need at least 2 of them for redundancy and depends on your site size my recommendation would be to have 3 of them located in different places. This is reducing the collision risk, ensuring you will keep the right level of service even if, sun, cold or simply age makes one of them stopping its service. This requirements means around 3.000€ investment you will have to renew every 5 years.
- On top of these gateways you need to consider the installation cost : the first time you will have to provide power and potentially network to a roof top and mobilize someone to configure and install the gateway on this roof. You can consider a cost from 1.000€ to 5.000€ the first time and we can assume about 1.000€ every 5 year for renewal.
- To make the gateway communicating you usually need a 3G communication primary or backup. Even if the objets communication is really light you have to consider all the keep-alive traffic, about 50Mb / month. The 3G communication will cost about 5€ / month per gateway. Assuming 900€ per 5 years.
- To manage your gateway you need a network kernel software ; you can find some some boxes playing this role, able to manage on site about 2.000€ but there is many options and the order of magnitude can be really large. So let’s take this assumption if you do not want to use TTN as a free solution.
- Do not forget your IS team will also have to monitor, manage, update the gateways. Initially the team will have to train on this technology, you will have to make a lot of meeting with building, security, purchasing team… and spend at least 20 men days and personal estimation 5 men days a year on this topic. Depends on your company we can estimate this to 40 days for 5 years and 10.000-20.000€.
- To let all of this you need also to provide electricity, let’s consider this as marginal, even if false.
Total cost of owner-ship of the infrastructure
Based on this, we get a 5 year TCO from 17.000€ to 30.000€ per site, trending to 10.000€ later on. Basically we are starting from 3400€ / year.
Regarding the usual price for network connectivity offered by public operator (as for Sigfox and LoRaWan), this is from 400 to 500 billable subscription per year.
It means, if you are not sure to have more than 500 devices in your sites you may really consider public networks instead of managing your own network. People said “no-one like subscription” but basically trends on IT are subscriptions and telecom at first. No-one want’s to manage its own 3G telecom network, why do you want to manage your LPWA network ?
For sure you may except to deploy tomorrow thousands of sensors… but will you really ? In the today chosen technology ? If this happens for real, let’s make a plan for a future transition to a private network or simply negotiate with your operator, at end, for it, smaller is always better than nothing.
I fully agree on the use of private LoRaWan network for testing, lab purpose where you want autonomy but as soon as you want to go in production, the real costs have to be considered and basically, for the same reason we are less and less hosting our servers for benefit of the cloud, we should go to public operators for managing our network, save money and gain on reliability.
Security is a wrong answer, as for Internet traffic, you just need to switch to “https”, it’s on your own. Public or private, over the air, data are the same and only frame level encryption with your own key will really protect you… when needed.