Your browser is not supported. Please update it.

4 October 2021

Truphone teams with Sony and Kigen to offer iSIM platform for IoT

Truphone, a London-based international mobile operator specializing in voice and IoT connectivity, has joined forces with chipset maker Sony Semiconductor Israel and Belfast-based SIM specialist Kigen to develop an integrated SIM (iSIM) package for global IoT deployment.

Sony Semi, formerly called Altair, and Kigen, which was spun out of ARM in November 2020, had worked separately on a proprietary version of iSIM technology for remote provisioning of IoT devices on networks using either of the cellular LPWAN protocols, NB-IoT and LTE-M networks.

Indeed, that iSIM capability from Sony Semi and Kigen had already been demonstrated in a proof of concept (PoC) during June 2021 by Soracom, another global provider of advanced IoT connectivity. Now Truphone has gone further by bringing that iSIM implementation to market in an ‘out-of-the-box’ IoT package aimed at international markets.

According to Sony Semi, the offering provides “global connectivity without roaming”. Truphone’s IoT connectivity platform has been integrated with the Altair line of cellular IoT chipsets, including the dual-band ALT1250 chipsets supporting both LTE-M and NB-IoT, as well as the single-mode ALT1255 chipsets offering only the latter. Altair, based in Israel, was acquired by Sony in 2016, finally being rebranded as Sony Semiconductor in 2020.

Sony Semi and Kigen have become leading evangelists for iSIM after working with Vodafone in 2020 on a formative iSIM deployment at German pharmaceuticals and life sciences giant Bayer. This came in the form of a printable NB-IoT-based tracking label costing €2 to monitor Bayer’s products as they percolate through its supply chain.

ARM was also involved in that project to integrate iSIM capability into a layer of printable silicon, incorporated in the communications module beside an also-printable battery, microprocessor, antenna, modem and two sensors. Vodafone provides the reference, ARM issues the blueprint, while Sony Semi designed the chip. The module came from another firm, Murata, a Japanese electronics components maker.

The key lay in the ease of application – almost like a postage stamp – and the low cost, which together opened a new vista for asset tracking among lower value commodities, rather than being confined to items worth well into three figures in dollars or Euros. This would not have been possible without iSIM and that particular case has helped galvanize that field.

Equally important, though, has been maturation of the standards, as we noted in May 2021 when the Trusted Connectivity Alliance (TCA) asserted in a paper that technology was now ready to underpin new IoT use cases. The document advocated global and open standards developed by the GSMA among others, ensuring that iSIM technologies are both interoperable and at least as secure as either removable or embedded SIM (eSIM).

The paper, entitled ‘Integrated SIM functionality: drivers, approaches to standardization and use cases’, defined an iSIM as an implementation of SIM functionality on a hardware tamper-resistant element (TRE), integrated into a host system-on-chip (SoC). It is an extension of the eSIM, which is a programmable SIM card incorporated in a device but still occupying a dedicated slot distinct from the SoC.

The eSIM was developed primarily for machine-to-machine (M2M) applications with the main saving in footprint coming from shrinking the SIM a little further and avoiding need for a connector. The iSIM took remote provisioning further by moving the SIM functionality from a dedicated chip into a secure enclave within either the application or modem SoC.

TCA evolved from the SIM Alliance in February 2020, reflecting the continued expansion of the global SIM industry and need for broader industry collaboration among all ecosystem participants beyond traditional SIM manufacturers. It now acts as a bridgehead uniting parallel standardization efforts, with GSMA and ETSI spearheading developments there as the two principal players.

The TCA is playing a role aligning these initiatives and in its paper hints that the era of traditional physical SIM could soon be over, as the functionality dissolves into secure zones within chips more generally.

Currently, the iSIM is an extension of the TRE (tamper resistant element) as a standalone secure element or a secure enclave, comprising hardware and low-level software providing resistance against logical and physical attacks, able to host secure applications along with associated confidential or cryptographic data. TREs, as we know, are now available in removeable, embedded and then most recently, the integrated form factors (that is SIM, eSIM and integrated SIM).