Carrier Grade LoRaWAN® Gateways Key Parameters
Many Telecommunication Engineers have been trained on or are aware of Carrier Grade requirements introduced in the late 1990s to ensure that telecom equipment is developed and tested to mission-critical standards as people, businesses, and government livelihoods and operations depend on them. The initial Carrier Grade requirements were focused on public wired and later wireless telecom infrastructures. Later the same Carrier Grade requirements were adopted to the critical infrastructures such as VoIP and the Internet at large.
The classic telecom Carrier Grade specifications focus on the Network Availability (so called 5 9s or 6 9s); Performance (best Key Performance Indicators for type of product); Security (product and network); and Maintenance (operation and evolution). For any product to meet Carrier Grade requirements there are many relative standards and product specifications they have to meet depending on the network and deployment. However, there are 12 key areas that any Carrier Grade product must address. The developers and operators should also understand the Carrier Grade LoRaWAN Gateway design implementation, specifications and their importance. Figure 1 represents four LoRaWAN Gateways designs that meet Carrier Grate performance requirements mentioned above.
Figure 1: Mega, Macro, Mobile and Cable Strand Carrier Grade LoRaWAN Gateways
Below are the important areas every developer should consider while designing and testing LoRaWAN® Gateways. Every operator should seek to verify before deploying the LoRaWAN® Gateways if they intend to operate them for 5-10 years without significant downtime, numerous issues, site visits or poor performance, all of which leading to significant Operator Cost increases or equipment replacements well before its time.
1. Does the Gateway support minimum 5 9s or 0.99999 availability (maximum 5 minutes/year down time)?
2. Does the Gateway meet 15+ year Mean Time Between Failures (MTBF) based on design and Failures in Time (FIT) analysis?
3. Does the Gateway support all SW & FW Updates and Upgrades, Configurations and Provisioning remotely and autonomously without ever visiting the Gateway site (a single visit can be more expensive than the Gateway itself and take days due to location, accessibility and weather conditions)?
4. Does the Gateway monitor its Digital, Radio, 3G-4G Modem, Backhaul and Power Supply subsystems to ensure they function normally and if not, do they raise an alarm and indicate what subsystem generated the alarm, or failed, and what are the remedial next steps?
5. Does the Gateway cause interference to other types of wireless systems, especially in the licensed bands because the Gateway does not have proper RF Band Pass filter at its Antenna (which runs the risk having the entire LoRaWAN® network shut down by FCC or other regulatory bodies until the interference is addressed)?
6. Do other wireless systems (3G, 4G, 5G, FM Radio, Digital Public Radio, TV Broadcast, GPS Re-transmit etc.) cause interference to the Gateway because it does not have proper RF Band Pass filters at its Antenna and effectively reduces the LoRaWAN® network coverage, reception reliability, overall network dependability and in many cases damage the Gateway LNA circuits?
7. Does the Gateway and the LoRaWAN® network incorporate security to ensure the network performance and security cannot be compromised at any level and the collected data is secured?
8. Is the Gateway design, features and performance optimized for a customer specific deployment and operation (or it is “one size fits all”) to save significant deployment and yearly Operating Costs as the Gateway cost is only 5% to 15% of Total Operator Cost when amortized over 5-7 years?
9. Does the Gateway design, Backhaul, 3G, 4G and 5G Modem support standard and product evolution for 5-10 years? In particular, are the 3G, 4G and 5G modems certified by the global cellular operators and will they support operator LTE releases for the next 5-10 years? It is for this reason Gateway vendors should use 4G CAT-6 modems to ensure optimal Rx and Tx performance with MIMO and operator long term support.
10. Does the Gateway have all of its external interfaces ESD and Lighting protected? Does the Gateway meet country and regional Regulatory and Safety Requirements (Safety requirements could carry criminal liability and void operator commercial insurance if the Gateway causes damages)?
11. Does the Gateway meet IP67, 5% to 100% condensing humidity, operate from -40˚C to +60˚C without any degradation and support -40˚C Cold Start (power up after -40˚C for 4+ hours)? Also, does the Gateway operate normally and meet its specifications across the entire input voltage range and at “four corners” that are defined as combination of Min and Max operating Voltage and Temperature?
12. Does the Gateway support comprehensive network level Operation, Administration & Maintenance (OA&M) at the entire LoRaWAN® network level to guarantee Operator lowest Operating Cost or Total Cost of Ownership?
If the Gateways selected for the IoT network do not meet the above requirements, then those Gateways will cost the operator significantly more on a yearly basis, and worse even increasing their cost YoY as the products age, becoming less reliable, causing more equipment downtime.
LoRaWAN® Network Operators Cost Drivers
The traditional cellular operators have on average 30 years of deployment and operation experience and have optimized their model to ensure the selected Basestation must guarantee high performance, network availability, and low operating cost. They don’t select the lowest priced Basestations as they know the network performance and operating cost and total network cost will suffer. This will not only make them less competitive, but also result in losing customers to competition, and not able to reinvest into growing and improving the network. For this reason, all wireless operators protect the true network cost and how they have optimized it – it is one of their key metrics that determines not just profitability, but future growth, market expansions, partnerships and M&A activity.
Today there are some LoRaWAN® operators that had to fix or replace the LoRaWAN® Gateways only after 1-3 years of operation. It is important to note that a replacement cost of LoRaWAN® Gateways in most cases is more expensive than the cost of the Gateways. Furthermore, the incremental cost due to the suboptimal quality of LoRaWAN® Gateways adds a minimum of 25% to well over 100% to the yearly Operating Cost of the LoRaWAN® Network.
Figure 2: LoRaWAN® Gateways Deployment at 110-foot Telecom Tower using a Boomer Crane
Now, let’s look at how the operator Total Network Cost is affected by only two parameters: Gateway Radio Performance and Reliability. A typical LoRaWAN® network cost for a mid-size city of 1.25 million people such as Calgary, Canada, is provided below in the table below.
The data provided in the table is a good approximation of a real-life network performance and cost by an operator with focus on optimizing the overall network cost. Anyone who would like to adjust any of the parameters or data can download the XLS from TEKTELIC website for their own use.
Table 1: Typical Simplified LoRaWAN Network Cost Numbers
The yearly cost to operate a LoRaWAN® network for a city similar size and density to Calgary, the total cost is estimated $1.38 million as provided in the Table 1. Here we assumed all deployed Gateways meet the telecom Carrier Grade performance previously discussed in this paper. In particular, we assumed the LoRaWAN Gateway Radio performance is not degraded because of its suboptimal Receiver or Transmitter sensitivity, linearity, or other impairments. We also assumed the collocated wireless systems do not interfere with the LoRaWAN Receive signals and the LoRaWAN Gateways are reliable and do not require additional site visits other than a typical maintenance visit every 24 months.
It is worth noting the LoRaWAN Gateway cost as a percentage of the site cost is only 3.3% on a yearly basis when amortized over 7 years. For some LoRaWAN network this number can be even a bit less, but it rarely exceeds 10%. In other words, the Operating Cost of a LoRaWAN network is highly dependent at the quality and reliability of the deployed LoRaWAN Gateways, but the is not that sensitive to the actual cost or the LoRaWAN Gateways itself as it represents a small percentage of the LoRaWAN network cost.
Indeed, the amortized LoRaWAN Gateway cost is very low compared to the total LoRaWAN network cost, even if it is amortized over 5 years instead of 7 years. However, the total LoRaWAN network cost is highly dependent at the LoRaWAN Gateways Radio performance and their reliability.
Just to show how dependent the total LoRaWAN network cost is on the Gateway performance itself, let’s reduce the effective LoRaWAN Gateway radius due to poorer Radio performance and at the same time increase the number of site visits due to poorer LoRaWAN Gateway reliability (alarms, failures, Gateway replacement free of charge, manual SW Upgrades, and other cost drivers) and incremental labor costs.
Table 2 below clearly indicates how sensitive the LoRaWAN® network cost is to the Gateway Radio performance and its reliability. If the LoRaWAN Gateways radius is reduced by 30%, what is insignificant reduction in dB terms, the total LoRaWAN Network Cost will approximately double to $2.8 million per year! And if each LoRaWAN® site requires a visit every 5 months, or 2.5 visits per year, then the LoRaWAN total network cost will further increase by $430 thousand per year! These are significant yearly cost increases that provide no incremental value to the operator or its customers. One could think of a courier service such as FedEx where only half the vehicles are working and the other half are always being fixed, but payments are being made consistently for the entire fleet.
Table 2: LoRaWAN® Network Cost as a function of Poorer Radio Performance and Reliability
Table 3 indicates the LoRaWAN® incremental network cost as a function of poor Radio Performance and Reliability when compared to optimal Carrier Garde LoRaWAN Gateway performance. Both tables clearly indicate the value of Carrier Grade Gateway and their performance considering two parameters, but there are more than 15 that impact the operator Total Network Cost or Ownership.
Table 3: LoRaWAN® Incremental Network Cost as function of Poorer Radio Performance and Reliability
Is 25%, 50%, or 100% increase of the operator yearly network cost significant or detrimental to the LoRaWAN® operator’s success? The answer depends on if the LoRaWAN® network is experimental and used for Proof of Concept (POC), early trial or large and commercial. For example, if a LoRaWAN® network is small and used for a POC with no real customers, does not need to support certain Service Level Agreement (SLA), and has only a handful of LoRaWAN® Gateways, then there is no real customer impact and the incremental yearly cost to run such an experimental POC network is very low. There could be a good reason to do so - one could procure lower cost LoRaWAN® Gateways or complete solutions to test the Use Case, conduct customer demos, or run the Network in parallel when negotiation with other Gateway vendors. In most cases, a trial or POC network does not cost a lot and does not put significant risk on the operator or enterprise future business.
However, if the operator or enterprise deploys a large commercial LoRaWAN® networks with 100s or even 1000s of LoRaWAN® Gateways, its paramount is to keep its yearly Operating Cost low, what amounts to the total Network Cost. To do so they need to deploy the most reliable and best performance Carrier Grade LoRaWAN® Gateways as was provided in Tables 1, 2 and 3.
Deployment of Carrier Grade LoRaWAN® Gateways will result not only in the Operators lowest total Network Cost, but the Carrier Grade Gateway will also result in the best practical outdoor and indoor coverage, high network reliability and availability, low interference, fewer device re-transmissions and longer device battery life.
A typical wireless operator success depends on the best coverage, most reliable level of services and lowest network Total Cost of Ownership. It has been the winning formula for most global cellular operators over 30 years, and it still applies to the cellular operators today. Most telecom professionals believe it also applied the LoRaWAN® operators and enterprises.