NB-IoT Deployment Mode Workbench

Compare in-band, guard-band, and standalone NB-IoT deployment choices.

Learner-ready NB-IoT deployment mode workbench with spectrum placement animation, LTE PRB impact, guard-band and standalone feasibility checks, frequency-band propagation notes, source links, and local desktop/mobile visual verification.

Cellular IoT Spectrum planning Deployment modes

NB-IoT Deployment Mode Workbench

Place the same 180 kHz NB-IoT carrier into in-band, guard-band, or standalone spectrum. The important lesson is that deployment mode is mostly a spectrum and coexistence choice; coverage also depends on band, radio planning, and coverage enhancement settings.

Diagnosis In-band is the fastest launch path, but it consumes one LTE PRB.

Mode In-band

LTE PRB cost 2.0%

Current phase Inventory spectrum

180 kHz carrier NB-IoT downlink occupies a narrow carrier that aligns with one LTE physical resource block: 12 subcarriers at 15 kHz.

In-band The carrier is placed inside an LTE carrier. It is quick to launch, but the LTE scheduler gives up one PRB for NB-IoT use.

Guard-band The carrier is placed near the LTE carrier edge. It avoids normal LTE PRB loss, but only works when the guard-band placement is allowed and clean enough.

Standalone The carrier uses dedicated spectrum, often a refarmed 200 kHz GSM channel. It is clean, but needs spectrum and more planning.

Scenario set

Deployment controls

Try a realistic operator situation, then step through how the network planner chooses a deployment mode.

Deployment mode In-band inside LTE carrier Guard-band at LTE edge Standalone refarmed carrier

LTE carrier bandwidth 5 MHz LTE carrier 10 MHz LTE carrier 15 MHz LTE carrier 20 MHz LTE carrier

50 PRBs available

Operating band focus 700 MHz low band 850 MHz low band 900 MHz refarmed band 1800 MHz mid band 2100 MHz mid band 2600 MHz high band

+5.8 dB path-loss advantage vs 1800 MHz proxy

LTE traffic load

55% busy LTE carrier

Guard-band condition Clean and allowed edge placement Tight guard-band or adjacent concern No usable guard-band placement

Refarmed 200 kHz channels

2 refarmed channels available

Planning priority Fast launch on existing LTE Protect LTE data capacity Deep indoor or rural reach Clean dedicated IoT carrier

Guided task flow

LTE spectrum Placement choice IoT carrier

guard

guard

Refarmed 200 kHz channel available for standalone NB-IoT

10 MHz LTE carrier 50 PRBs, one 180 kHz NB-IoT anchor

NB-IoT carrier 180 kHz anchor

Inventory the spectrum Start by identifying what the operator already has: an LTE carrier, enough guard-band room, or a refarmed 200 kHz channel.

Deployment decision

The result is a planning diagnosis, not a promise that every regulatory band and vendor configuration supports every placement.

Planning bars

These bars separate LTE PRB cost, coexistence risk, dedicated spectrum availability, and low-band propagation help.

Spectrum fit signals

The selected mode is checked against the resources it needs.

Event log

Each row links the animation to an engineering decision.

Deployment quick reference

In-band NB-IoT occupies one LTE PRB inside the LTE carrier. Good for quick rollout on existing LTE, but it consumes LTE scheduler capacity.

Guard-band NB-IoT is placed near an LTE carrier edge. It protects normal LTE PRBs, but edge placement and emissions need careful planning.

Standalone NB-IoT uses a separate carrier, often refarmed from 200 kHz GSM spectrum. It avoids LTE PRB impact, but needs dedicated spectrum.

PRB math One LTE PRB is 12 subcarriers times 15 kHz, or 180 kHz. A 10 MHz LTE carrier has 50 PRBs, so one PRB is a 2% teaching cost.

Coverage caveat Deployment mode does not automatically create coverage. Coverage comes from link budget, frequency band, repetition, receiver design, and network configuration.

Anchor carrier This workbench focuses on the anchor carrier placement. Real deployments may add non-anchor carriers and vendor-specific scheduling behavior.

Technical notes and primary sources

What is exact here

• NB-IoT has in-band, guard-band, and standalone operating modes.
• A 180 kHz NB-IoT carrier aligns with one LTE PRB in the in-band teaching view.
• LTE downlink PRB counts used here are the standard nominal counts for 5, 10, 15, and 20 MHz carriers.

What is simplified

• The LTE cost bar is a PRB-count proxy, not a full scheduler throughput model.
• The low-band advantage uses free-space path-loss difference relative to 1800 MHz; real coverage also depends on clutter, antennas, power, and interference.
• Guard-band fit is simplified into clean, constrained, or unavailable conditions.

Primary source links

3GPP TS 36.300: E-UTRA and E-UTRAN overall description 3GPP TS 36.211: E-UTRA physical channels and modulation 3GPP TS 36.213: E-UTRA physical layer procedures 3GPP TS 36.331: E-UTRA RRC protocol specification 3GPP TR 45.820: Cellular system support for ultra-low complexity low throughput IoT

Practice prompts

Fast rollout Select the "Fast launch" scenario. Increase LTE load above 85%. Explain why in-band is still fast but may be less attractive for a busy LTE carrier.

Capacity protection Select guard-band mode and set the guard condition to constrained. Explain what must be checked before this mode is safe.

GSM refarm Select standalone mode and set refarmed channels to zero. Explain why standalone becomes blocked even though it would avoid LTE PRB cost.