Choosing IoT connectivity: Wi-Fi, Bluetooth LE, LoRaWAN, NB-IoT, LTE-M and cellular

Connectivity is a product decision, not a detail

The radio inside a connected device shapes almost everything else: battery size, enclosure, bill of materials, installation process, recurring costs and even which features are possible. A temperature sensor that reports twice an hour from a basement has very different needs from a vehicle tracker or a smart door lock. Choosing the radio late, or choosing it because the team already knows it, can force a costly redesign later.

This guide compares the mainstream options, explains the trade-offs and sets out a practical way to decide.

The trade-off triangle: range, power and data rate

Every wireless technology balances three things:

Range: how far a device can be from the nearest gateway, access point or tower.
Power: how long a device can run on a battery.
Data rate: how much data it can move, and how quickly.

You can usually have two at the expense of the third. Wi-Fi offers high data rates and modest range but uses more power. Low-power wide-area networks (LPWANs) such as LoRaWAN and NB-IoT offer long range and long battery life, but only for small, infrequent messages. Bluetooth Low Energy offers low power and decent data rates, but over short distances.

Two other factors matter just as much: who owns the network (you, a mobile operator or a third-party provider) and what it costs to run (hardware only, or a recurring subscription per device).

Wi-Fi

Wi-Fi is the obvious choice for mains-powered devices inside buildings that already have it: cameras, displays, appliances and gateways. It carries IP traffic natively, supports high throughput and needs no extra infrastructure.

Its drawbacks for IoT are power and onboarding. Staying connected to an access point draws far more energy than LPWAN radios, and getting a headless device onto a customer’s network (entering the network name and password) needs a well-designed provisioning flow.

Newer generations help. The Wi-Fi Alliance states that Target Wake Time (TWT) in Wi-Fi CERTIFIED 6 “significantly improves network efficiency and device battery life”.

Wi-Fi HaLow is a separate variant aimed at IoT. According to the Wi-Fi Alliance, it operates in sub-1 GHz spectrum, offers approximately 1 km of range with good wall penetration, and can support months to years of coin-cell battery life. Availability depends on whether suitable sub-GHz spectrum is permitted for it in your target market, so check local regulations before committing.

Best for: mains-powered devices in buildings with existing Wi-Fi, video and anything that needs high throughput.

Bluetooth Low Energy (BLE)

Bluetooth LE was designed for very low-power operation. The Bluetooth SIG’s technology overview lists the key specifications:

operates in the 2.4 GHz band, using 40 channels with 2 MHz spacing;
supports point-to-point, broadcast and mesh topologies;
offers data rates of 1 Mb/s and 2 Mb/s, plus “Coded” modes at 500 kb/s and 125 kb/s that trade speed for better receiver sensitivity;
supports positioning through presence detection, direction finding and distance measurement.

BLE’s great advantage is that every modern smartphone has it. That makes it the default for wearables, medical devices, fitness equipment and anything set up or controlled from a phone app. It is also widely used as the provisioning channel for Wi-Fi devices: the phone connects over BLE and passes the Wi-Fi credentials to the device.

Its limitation is that it does not reach the internet on its own. A device needs a phone, a hub or a gateway to relay its data.

Best for: wearables, phone-controlled products, short-range sensors, indoor positioning and device provisioning.

LoRaWAN

LoRaWAN is an LPWAN specification maintained by the LoRa Alliance. The LoRa Alliance describes it as a “Low Power, Wide Area” networking specification that runs in unlicensed radio bands and is an ITU-approved international standard. Its architecture is a “star-of-stars”: end devices send messages to any gateway in range, gateways forward them over ordinary IP links to a network server, and the network server passes them to your application. The Alliance cites range of up to 15 km in rural areas and battery life of more than 10 years, though real figures depend on the environment, message frequency and payload size.

Device classes

The LoRaWAN Link Layer specification v1.0.4 defines three classes of end device:

Class A: every device must support it. After each uplink, the device opens two short receive windows. It is the lowest-power mode, but the server can only send data shortly after the device has transmitted.
Class B: adds extra receive windows at scheduled times, synchronised by beacons from the gateway, so the server knows when the device is listening.
Class C: keeps the receiver open almost continuously, giving the lowest latency for downlinks at the cost of higher power use.

Regional plans, including India

LoRaWAN uses different frequency plans in different regulatory regions. The LoRa Alliance’s Regional Parameters (RP002-1.0.2) include an IN865-867 plan for India, with its own default channels, data rates and receive-window settings. Devices and gateways must be configured for the correct plan.

Private or public network

Because LoRaWAN uses unlicensed spectrum, you can run your own gateways and network server, which suits campuses, factories, farms and utilities where you control the site. Alternatively, you can use a public or community network where one covers your area. The LoRa Alliance also lists firmware updates over the air (FUOTA), multicast, relay and geolocation among the specification’s features.

Best for: battery-powered sensors sending small, infrequent readings across a large site, especially where you want to own the network.

NB-IoT and LTE-M (cellular LPWAN)

NB-IoT (Narrowband IoT) and LTE-M (LTE for Machine-Type Communications, also called eMTC) are cellular technologies designed for IoT and standardised by 3GPP, the body behind mobile network standards. According to 3GPP, both were developed in Release 13, alongside EC-GSM-IoT.

They run on mobile operators’ licensed spectrum, so you need a SIM (or eSIM) and a data plan, but no infrastructure of your own.

NB-IoT

3GPP describes NB-IoT as designed for ultra-low device complexity and energy efficiency. It can operate in a system bandwidth as low as 200 kHz, and can be deployed in three ways: as a stand-alone carrier, inside an LTE carrier or in an LTE guard band. It suits stationary devices that send small amounts of data, such as utility meters, parking sensors and environmental monitors.

LTE-M

LTE-M uses a larger bandwidth than NB-IoT. 3GPP notes that it offers lower latency and higher throughput than NB-IoT and can support services such as voice over IP. It includes low-cost device categories such as Cat-M1 and Cat-M2. That makes it a better fit than NB-IoT for devices that need quicker responses, larger or more frequent transfers (such as firmware updates), or voice.

Efficiency for small messages

Release 13 also introduced a control-plane optimisation for cellular IoT that, according to 3GPP, enables efficient transfer of “small, infrequent packets”, which is exactly the pattern most sensors follow.

A path into 5G

NB-IoT and eMTC are not legacy technologies. 3GPP’s submission to the ITU for IMT-2020, the formal 5G standard, includes both as components alongside 5G New Radio.

Best for: devices spread across a city, region or country where you cannot install gateways, and products that must work out of the box wherever there is operator coverage.

Conventional cellular (4G and 5G)

When a device needs real bandwidth (video, large file transfers, rich telemetry, in-vehicle systems), full LTE or 5G is the option. Power consumption and module cost are higher, so these devices are usually mains or vehicle powered. Many industrial gateways use cellular as their backhaul, with local devices connected over BLE, Wi-Fi or LoRaWAN.

Comparing the options

The table below is a qualitative summary. Actual range, data rate and battery life depend on the module, antenna, environment, message pattern and network configuration.

	Wi-Fi	BLE	LoRaWAN	NB-IoT	LTE-M	4G/5G
Typical range	Building	Room to building	Kilometres	Operator coverage	Operator coverage	Operator coverage
Power use	Higher	Very low	Very low	Very low	Low	Higher
Data rate	High	Moderate	Very low	Low	Moderate	High
Spectrum	Unlicensed	Unlicensed	Unlicensed	Licensed	Licensed	Licensed
Who runs the network	Customer	Phone/hub	You or a provider	Operator	Operator	Operator
Recurring cost	None	None	Low or none	Subscription	Subscription	Subscription

A practical decision process

Map the data. How many bytes per message, how often, and does the device need to receive commands or firmware updates? A few bytes every 15 minutes points to an LPWAN; video rules it out.
Map the power budget. Is the device mains powered, rechargeable or on a primary battery that must last years? Work out an energy budget per message, not just a headline battery claim.
Map the location. Indoors or outdoors, fixed or moving, one site or many, urban or rural? Check real coverage with test devices on site, not just coverage maps.
Decide who owns the network. Running your own LoRaWAN gateways means control and no per-device fees, but you operate them. Cellular means no infrastructure, but a subscription for every device and dependence on operator coverage and roaming agreements.
Think about the whole life. Devices may be in the field for a decade. Consider module availability, network longevity, certification and how you will deliver security updates over the chosen link.
Prototype early. Build a small number of devices on the shortlisted radios and measure range, power and reliability in the real environment before committing to a design.

Many products combine radios: BLE for set-up and local control, plus Wi-Fi, LoRaWAN or cellular for the main data path. Designing for that from the start is far cheaper than adding it later.

Security applies to every option

Whatever the radio, the device still needs unique credentials, encrypted communication, authenticated firmware updates and a way to be retired safely. The radio choice affects how you implement these (in LoRaWAN, for example, a device that joins over the air (OTAA) holds an AES-128 root key, the AppKey, from which session keys are derived when it joins, according to the Link Layer specification), but it does not remove the need for them.

Sources

Facts in this article were checked against the linked sources on 9 October 2026. Rules, prices and standards change; check the source before relying on a detail. This article is general information, not legal or financial advice.