Remote SIM & Virtual SIM
OmniWeb can present any SIM to any modem over the network, and can even present a SIM that does not physically exist — emulated from a saved card image plus the subscriber's keys held in the HSS. This turns a rack of SIM readers, card emulators ("cardems") and modems at one or more sites into a shared pool: any tester can drive any subscriber profile against any modem without walking a plastic SIM to a card slot.
This page is the operations guide for that capability. The inventory half — discovering which SIMs are in which readers — is covered in SIM Bank; this page covers presenting a SIM (real or virtual) to a modem and using it in a test. Saving a card's file system as a portable profile package — and using one to back a virtual SIM — is covered in SIM Images (SAIP Profile Packages).
Table of Contents
- Architecture Overview
- Concepts
- The SIM Bank — what's where
- Remote SIM — connect a SIM to a cardem
- The Cardem Console
- Virtual SIM — a subscriber with no physical card
- Using a SIM in a Roaming Test Book
- Troubleshooting
Architecture Overview
A SIM reader bank, one or more card emulators, and the modems under test connect to OmniWeb through its device agents. A central broker maps a chosen SIM slot to a chosen cardem; the cardem then presents that SIM to the modem plugged into it.
For a virtual SIM, the reader bank is replaced by a software card built from a saved SIM image and the subscriber's keys — everything else is identical:
Concepts
| Term | Meaning |
|---|---|
| SIM bank | A set of smart-card readers on an agent, published so their SIMs can be presented elsewhere. Each populated reader is one slot. |
| cardem | A card-emulator board (USB) that pretends to be a SIM towards a modem plugged into it. It plays back whatever card it is mapped to. |
| Slot map | The binding "present this SIM slot to that cardem". Creating it connects the two across the network; removing it disconnects them. |
| Modem under test | The modem behind a cardem. It attaches to the live network using whichever SIM the cardem is presenting. |
| Virtual SIM | A software card built from a saved SIM image + a subscriber's keys, presented to a cardem exactly like a real SIM — no physical card required. |
The SIM Bank — what's where
The SIM Bank page lists every reader slot on every connected agent, grouped by agent, so the bank layout is the truth — empty, unreadable, and in-use slots all show, not only populated ones.
Each row is one physical reader. The status chip shows whether a card is present and readable; the row then shows the SIM's identity (ICCID, IMSI, MCC/MNC, country, operator name). Readers held by an active emulation session show as In use. Persisted SIMs whose reader is currently offline appear under Previously seen and reappear when the agent reconnects with the SIM inserted.
| Status chip | Meaning |
|---|---|
| SIM | A card is present and its identity was read. |
| Card present | A card is physically seated but its identity could not be read (e.g. an incompatible reader/card pairing). |
| In use | The reader is held by a remote-SIM/emulation session right now. |
| Empty | No card in the slot. |
Per-row actions open the SIM Filesystem explorer or the APDU Terminal for that exact slot, and Rescan re-reads an agent's readers on demand.
Remote SIM — connect a SIM to a cardem
The Remote SIM page is where you bind a SIM to a cardem. Bindings work across agents and sites — the SIM can be in a reader at one location and the cardem/modem at another.
Steps
- Start the SIM bank on the agent that holds the readers (Start bankd). This publishes its reader slots.
- Start the cardem client for the card emulator you want to use (Start client). This binds the cardem so a SIM can be mapped to it.
- Under Connect a SIM, pick a published slot and choose a cardem to bind it to. The mapping is created and shows under Active mappings as ACTIVE.
- The cardem now presents that SIM to its modem. Reset the modem (see the cardem console) so it reads the newly-presented SIM and attaches.
Global Reset tears down all mappings and returns every cardem to an idle state — use it to recover from a confused test bench.
| Field (Active mappings) | Meaning |
|---|---|
| State | ACTIVE once the cardem is presenting the SIM. |
| SIM (bank/slot) | Which agent's bank and slot the card lives in. |
| ICCID | The SIM presented. |
| Cardem (client/slot) | Which cardem (and which agent) is presenting it. |
| By | The operator who created the mapping. |
The Cardem Console
In Devices, a card emulator is shown as its own device type (ngff-cardem),
alongside modems and phones — it is never opened as a phone. Unknown device types
are labelled plainly rather than guessed.
Opening the cardem gives a dedicated console for the emulator and its modem.
| Control | What it does |
|---|---|
| Start client | Binds the cardem as a remote-SIM client so a SIM can be mapped to it. |
| Reset modem | Re-presents the emulated card, which makes the modem re-read the SIM and re-run attach — the way you "swap the SIM" without touching hardware. |
| Remote SIM | Connect or disconnect which remote SIM is presented to this cardem. |
The SIM source panel states honestly what is and isn't available: the cardem feeds the modem a remote SIM. Presenting a local card seated on the emulator board is not offered here yet, and the console says so rather than showing a control that does nothing.
Virtual SIM — a subscriber with no physical card
A virtual SIM lets a modem attach as a subscriber you do not have a SIM for. It is built from two things you already have:
- A base SIM image — a saved snapshot of a real card's file structure (any compatible test SIM works as the base; see SIM Images).
- The subscriber's identity and keys from the HSS — the IMSI and authentication keys of a subscriber already provisioned in the network.
OmniWeb combines them into a software card that answers the modem's file reads from the image and answers the network's authentication challenge using the HSS keys — overlaying the chosen subscriber's IMSI. Presented through a cardem, the modem cannot tell it from a plastic SIM: it reads the IMSI, runs authentication, and attaches to the live network.
When to use it
- Reproduce a specific subscriber's roaming or attach behaviour without sourcing their physical SIM.
- Exercise many provisioned subscribers against one modem, back to back.
- Test profiles that only exist in the HSS (newly provisioned, pre-shipment).
What it proves. A modem on the bench has attached to the live network
(registered, home network) as an HSS subscriber for which no plastic SIM
exists — reading that subscriber's IMSI and completing the network's
authentication entirely from the virtual card.
A dedicated Virtual SIM Reader element — where you "load" a virtual SIM from a chosen image and subscriber and present it like any other reader slot — is the next step on this capability. Today the virtual card is wired through the same Remote SIM broker and cardem path described above.
Using a SIM in a Roaming Test Book
Roaming Test Books (GSMA IR.38 / IR.48) can drive the SIM presentation as part of a run. In a test book's Run Tests panel you can choose:
- a SIM (by ICCID / IMSI) — tracked by identity, its current reader resolved automatically at run time, and
- a Cardem modem — the cardem the SIM is emulated to.
Present SIM to cardem establishes the mapping before testing; Go — Run All Tests presents the SIM first (when both a SIM and a cardem are selected), then reads the IMSI and runs the data cases. If the SIM is not currently in a reader, or the cardem's client is not running, the panel says exactly why instead of silently running against the wrong card.
See Test Devices and the test-book documentation for the rest of the IR.38 flow.
Troubleshooting
A SIM doesn't appear in the bank
Symptoms: a reader is plugged in but no slot (or an empty slot) shows.
Possible causes & resolution:
- The card isn't seated, or the reader/card pairing can't power the card — the slot shows Card present or Empty. Re-seat the SIM.
- The reader was just plugged in — readers are re-scanned on hot-plug, but you can force it with Rescan on the agent's group.
The modem won't attach after connecting a SIM
Possible causes & resolution:
- The modem hasn't re-read the SIM. Use Reset modem on the cardem console to re-present the card.
- The mapping isn't ACTIVE — confirm under Active mappings on the Remote SIM page that the SIM is bound to the right cardem.
- The subscriber isn't provisioned (or is barred) in the serving network's HSS.
"Card present (unreadable)" on a reader
Symptoms: a card is detected but its identity can't be read.
Resolution: that reader cannot talk to that card (commonly a voltage/protocol mismatch on inexpensive readers). Move the SIM to a different reader in the bank.
Virtual SIM: modem reads the card but doesn't attach
Possible causes & resolution:
- The chosen subscriber must be enabled and fully provisioned (with a data profile) in the HSS for the serving network.
- The base image must come from a compatible card type. Re-capture the base image from a known-good SIM if init stalls.