The Indoor-Outdoor IoT

Thoughts on an IoT blind spot

Two IoT Arenas

• Companies competing to sell you their wireless IoT connectivity technology can be thought of as competing in one of two separate “arenas”: an indoor arena or an outdoor arena.
• The indoor arena is typically dominated by low power, local area networking (LPLAN) technologies focusing on home automation. ZigBee, Z-Wave, and Control4 are well known examples. Use cases beyond home automation include enterprise/industrial automation, whose users reluctantly adopt the same tech (e.g. Zigbee smart meters) or proprietary alternatives (e.g. Honeywell alarm systems). Most operate in the tragically overcrowded 2.45GHz unlicensed band. Short range, high levels of interference (and returned merchandise), weak battery life. And 99% of their customers are using these technologies for indoor use cases.
• Some of these offer real-time indoor location capabilities to help find an object located in a building or warehouse to within a few feet of precision. Since GPS can’t work indoors, this is how it’s done. Some of these also offer mesh networking features, sometimes as a way to overcome the innate short range of the technology, but usually disguised under a marketing gimmick known as “self-healing.”
• WiFi is making a new push at joining the indoor IoT arena with a reasonable likelihood of success due to access point footprint, though not sufficiently low power to make a serious run at battery-powered endpoints.
• Omitted here: one-way passive RFID (great, niche technology) and one-way Bluetooth low energy (hyper-short range personal area networking, not even local area networking).
• The outdoor arena is where the most intense IoT connectivity battles are taking place today. Cellular and satcom have promised long range/wide area IoT for years resulting in steady but low volume success, and almost always tied to use cases where mains electric power is available at the endpoint. Battery-based versions of these have largely failed so far due to form factor, price point, and of course battery life weaknesses. Viable outdoor solutions using battery power (e.g. LPWAN’s) are relative newcomers disrupting the outdoor arena.
• New entrants to the outdoor arena are arriving via long range, low power wide area networking (LPWAN) technologies, which are challenging the need for mains power in long-range outdoor IoT use cases. LoRa and SigFox in unlicensed bands, and NB-IoT, LTE Cat-M, and other LTE-based efforts in licensed bands). All carry question marks regarding actual vs. promised performance (e.g. NB-IoT) or scalability claims (e.g. LoRa) pending broader adoption, but there is sufficient evidence now to argue we are really turning a corner in bridging low power with long, multi-kilometer range. But nearly all LPWAN use cases being talked about are outdoor-only.

The Indoor-Outdoor Orphans

• One challenge to the two-arena segmentation approach of the IoT is those use cases that straddle both indoor and outdoor arenas.
• Three immediate examples come to mind:

1. Supply chain. Precisely locating cartons of high-value pharmaceuticals during shipment or while stored in a warehouse or medical facility.
2. Access control. Precisely locating an outside contractor or hospital patient within a secure building as well as within a campus or metropolitan area.
3. IT asset management. Precisely locating a laptop with PCI or PHI data as it moves within your 10-story headquarters building as well as around a large campus.

• Today, use cases that by definition straddle both arenas must instead compromise and play in one arena. Example: tracking cattle on a ranch via short-range ZigBee chokepoints scattered around a ranch. Provides nominal and non-real-time visibility into the location/health of the cow, but well short of what ranchers really need (e.g. being able to find a lost cow somewhere on a 1,000 acre ranch or to know.)
• LPWAN solutions for outdoor location rely on GPS. Good for outdoor location, but no good for indoor location. While LPWAN’s can and will be used for indoor sensing applications (e.g. what is the temperature of the sensor in the walk-in freezer?), precise indoor location (e.g. where is Mike’s laptop) is unaddressed in any of the new or emerging LPWAN networking protocols. NB: real-time trilateration via networking stacks like LoRaWAN is unavailable at this time thus GPS is the near-universal means to achieving real-time outdoor location precision among LPWAN’s.
• Low power indoor LAN solutions usually rely on received signal strength or time-based location systems, relying on a series of reference points to assist in calibration. But low power LAN’s (short range, remember) cannot address outdoor use cases.
• Thus, indoor-outdoor use cases are a “blind spot” for the IoT, with few straightforward solutions for addressing both short of using multiple radios and exposing a horizontal application opportunity.
• Indoor-outdoor feature set requirements: long range-capable, fully bi-directional comms, low power, low price point, and real-time indoor location capabilities. NB: Increasingly, and for multiple reasons, real-time comms will be required for both indoor and outdoor use cases, but this is subject of another post.

A Third IoT Arena

• With LPWAN’s, it’s easy to redraw our landscape maps and create a de facto third, hybrid arena that bridges the first two, which I’ll just call “indoor-outdoor IoT.”
• Indoor-outdoor IoT use cases require a) long range, low power outdoor connectivity b) outdoor location precision, typically via GPS, c) low power indoor connectivity and d) indoor location precision to ~1 meter or less, typically via a real-time, reference point-based system.
• LPWAN’s are a huge step towards solving for the indoor-outdoor IoT. But as solutions today, they are incomplete.

Potential Remedies

1. Using multiple radios is the traditional solution to bridging use cases like these. To cite one obvious example: smartphones host both long range (LTE) and short range (WiFi, BT, NFC) connectivity options, albeit in a package priced at hundreds of dollars. Multiple radios add to an endpoint’s bill of materials, and in addition often require additional memory as well as antenna and other sacrifices. Hypothetically, an endpoint could contain both a Zigbee and a NB-IoT radio, but this means creating two parallel access point systems, among other drawbacks.
2. Reflashing existing silicon and re-using existing antenna in order to accommodate a software-defined radio is a slightly better solution. It might mean limiting your radio choices to those available using an existing antenna or might mean re-designing the antenna to accommodate both radios. It might also mean adding additional memory, which may or may not fit your budget. But it still requires parallel access point systems, etc.
3. Same as #2, but interleave an existing firmware stack (e.g. LoRaWAN, NB-IoT) with additional features to accommodate real-time indoor location. In other words, the long-range, low power WAN capability operates in its “native” mode unless it’s asked to operate in enhanced mode in order to facilitate indoor location. Or vice-versa. This is the approach we are taking at my company and has the added benefit of requiring only minimal incremental memory if any, since our stack already compiles into less than 20kb.

Takeaways …

• A two-arena segmentation model giving way, in the short term, to a three arena model as as a) there are use cases that straddle both the indoor and outdoor arenas and b) we now have technologies that can solve for both. The three-arena model will morph into a single arena in the long run. Or sooner.
• The market opportunity of the indoor-outdoor arena is significant even in the short term. The sheer number of measurable things and people that move between indoor to outdoor environments is very large.
• If you are reading this and daydreaming about use cases that fall within this third indoor-outdoor arena, “things that move” is a good attribute for helping to identify use cases. Things that are battery powered are a close second.
• Companies in the outdoor arena at a minimum should be examining opportunities in the indoor-outdoor IoT. More aggressive participants may realize that there is little preventing them — from a technology standpoint — from competing directly in the indoor arena.
• Companies competing in the indoor arena should therefore expect encroachment by LPWAN’s capable of competing indoors. Since most LPWAN’s — all things being equal — offer better indoor signal propagation and rough pricing parity, indoor arena participants will want to consider adding LPWAN capabilities to their product lines.
• Bonus takeaway: solving for the indoor-outdoor IoT helps to solve for some deeper business process/big data challenges that the first two arenas can’t really solve on their own: associating a mobile person or thing with a fixed person or thing.

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