Sierra Wireless MC7455 module

The MC7455 is a high-speed 4G wireless M2M module that can be embedded in a motherboard, mini-PCI to M.2 adapter, or printed circuit assembly to deliver wireless cellular networking connectivity to host devices like laptops, tablets, and M2M hardware.

This small form factor module can also be used to create custom cellular modems/routers. It is installed by being inserted into an expansion slot or electrical connector on the motherboard of a device and operates as an expansion bus to add cellular networking functionality to the host device. Operating as a wireless modem this PCI Express Mini Card also provides:

• Long Term Evolution (LTE)
• Universal Mobile Telecommunications System (UMTS)
• Global Navigation Satellite System (GNSS)

Key features of the MC7455 cellular modem include:

1. Network switching functionality is supported by up to three different pre-installed firmware. This enables sub-second over the air switching to the best available and compatible carrier in multi-network environments.
2. Dual Sim Single Standby (DSSS) functionality enables the wireless modem to work with two modems with one SIM on and one SIM on standby at any given time. The modem can switch between the network SIMs when needed to remain connected.
3. The MC7455 receives secure automatic updates to its firmware Over The Air (OTA). This ensures that the module functions with the most up-to-date software and remains secure. The modem is programmed to receive updates that are transferred wirelessly and only the cellular modem is updated not the host device (e.g. router) it is installed in.
4. The Sierra Wireless MC7455 modem is compatible with the following carriers:
   • VERIZON
   • AT&T
   • SPRINT
   • BELL
   • VODAFONE ROGERS
5. The MC7455 wireless module carries the Internet Protocol (TCP/IP) stack. LTE is an all-IP mobile technology and routinely utilizes IP routing protocols to route its data traffic. This set of communications protocols in the module support end-to-end communication over the internet via the cellular carrier and following the Internet Engineering Task Force (IETF) standards.

Technical Specifications of the Sierra Wireless MC7455:

• The dimensions of the Sierra Wireless LTE modem are 51 millimeters in length, 30 millimeters in width, and 2.7 millimeters in thickness. Its form factor is mini PCIe (full size).
• Its operating temperature range is -40 degrees Celsius to +85 degrees Celsius (-40 degrees Fahrenheit to 185 degrees Fahrenheit) compatible with rugged and industrial applications.
• This 4G/ LTE wireless card provides LTE Category 6 connectivity. The LTE User Equipment (UE) Category determines the uplink and downlink data rate of devices like routers, phones, and laptops in which the MC7455 modem is installed. Category 6 is LTE-Advanced (LTE-A), which has a peak downlink data rate of 300 Mbps and a peak uplink data rate of 50 Mbps.
• The MC7455 modem supports both 3G and 4G/LTE frequency bands, including;

• Its GNSS functionality is compatible with the leading Satellite navigation systems, including GPS, Galileo (European Union), BeiDou (China), and Glonass (Russian Federation).
• The Sierra Wireless MC755 also carries software interfacing to enable it to be compatible with Windows 7, Windows 8, and Windows 10. It also has drivers forLinux and the Android Radio Interface Layer (RIL).
• It is compatible with the following interfaces:
  • USB 2.0 High Speed is a high bandwidth version of USB with a peak signaling rate of 480 Mbps.
  • USB 3.0 is also high-speed and capable of achieving a signal transfer rate of up to 5 Gigabits per second.
  • It carries four General Purpose Input/Output (GPIO) digital signal pins.
• The MC7455 carries two Smart Identity Module (SIM) interfaces in-line with its dual SIM functionality. The wireless baseband processor of the cellular modem is interfaced with the SIM in compliance with ISO/IEC Smart Cart interface requirements and the relevant cellular standards. The interfaces are Class-B (2.95 V) and Class-C (1.8 V) interfaces.
• This cellular modem can be controlled or programmed via an application programming interface (API) but is most commonly set up using AT commands which are explored below.

Antennas for the Sierra Wireless MC7455 mini PCI card

The Sierra Wireless MC7455 requires a multiband 2x2 MIMO antenna arrangement using main and auxiliary external antennas to deliver LTE connectivity. The main path (ANT1), diversity path (ANT 2), and GNSS antennas should be omnidirectional.

The antennas are not supplied with the wireless modem. Purchase LTE antennas for the Sierra Wireless MC7455 modular here. In the absence of LTE, high-quality 3G connectivity is attained using the main and auxiliary antennas in an antenna diversity arrangement. This is achieved by the direct connection of two cellular antennas, ANT1 and ANT2.

The MAIN (ANT1) antenna should support the following frequency bands:

• 669 to960 MHz
• 1710 to 1995 MHz
• 2110 to 2170 MHz
• 2300 to 2690 MHz

The AUX (ANT2) antenna should support the following frequency bands:

• 717 to 960 MHz
• 1805 to 1995 MHz
• 2110 to 2170 MHz
• 2300 to 2690 MHz

A third GNSS antenna can be connected to satellite navigation and location services. Suitable GPS antennas for the Sierra Wireless MC7455 module can be found here.

The MC 7455 module is compatible with the following satellite navigation systems:

• GPS 1575.42 MHz
• BeiDou 1561.098 MHz
• Galileo 1575.42 MHz
• GLONASS1602 MHz

Antenna connectors for the Sierra Wireless MC7455 cellular modem

The MC7455 has three Hirose U.FL connectors that are the only radio frequency connection points on the module for the attachment of antennas. The three connection points are as follows:

1. MAIN LTE Connector: Transmit/Receive path

2. GNSS Connector: Dedicated connection for GPS and other SatNav technologies

3. AUX LTE RF Connector: Can be used for MIMO and other diversity schemes or GNSS

Antennas are attached to the module using a 3mm by 3mm Hirose U.FL connector. A U.FL connector tool should be used to make the connection. Antennas are connected via the 3 U.FL connector jacks at the top of the module.

U.FL to Bulkhead SMA connector pigtails are used to connect the module to a wideband cellular antenna.

The antenna system is a 50 Ohm impedance system and connections. Mounting holes on the module on the left and right of the RF connectors are used to ground the module to a PCB or device chassis via a bulkhead SMA connector.

Additional points

• The three output signals can be configured for specific operating bands by using a customer-defined external switch control.
• Antenna gain and cable losses need to be optimized for the best performance. The recommended return loss is specified as 10dB for each frequency band used.
• Antennas should be located away from sources of EMI with cabling/connectors that are properly matched.
• The specified VSWR for ANT1 and ANT2 should be less than 2:1.
• The AUX antenna receives diversity functionality that can be enacted or disabled using a specific AT command function.

Development kits for the Sierra Wireless MC7455

The MC7455 wireless module can be used for commercial, industrial, or recreational hardware development projects and prototyping as part of a Development Kit. Printed Circuit Board kits provide a robust hardware testing environment for applications that require cellular connectivity. The use of a development kit also supports the development of complementary software for the intended application.

The Developer Kit supports the testing and use of the MC7455 module. It includes power supply/adapters, two 2G/3G/4G LTE dipole wide-band antennas, and connectors. The module is mounted and grounded in the center of the PCB. The PCB carries a USB connector that can supply power and a connection point to a host device.

Important points about the Sierra Wireless MC Series Development Kit

• The MC series development kit functions as a test point only for MC series cellular networking modules, including MC7455.
• It is for LTE product development and has a single PCI slot for the MC7455 card.
• The Kit is used to develop hardware applications that require LTE connectivity, usually IoT / M2M, while simultaneously authoring the relevant software.
• The MC Dev Kit board has no WiFi connectivity chipset or radio module on board.
• A version of the Sierra Wireless MC Series Development Kit carries 5 SMA connectors. Three of the SMA connectors on the board connect to the MAIN, AUX, and GNSS antennas. None of the 5 SMA connectors connect to WiFi. 2 SMA connectors are redundant. This particular Dev Kit was likely to have been designed with 5 connectors to accommodate a card that may have carried more antennas but probably never released.
• If a WiFi radio is required an alternative development kit will need to be sourced. Alternatively, Sierra Wireless has released MangOH boards that have a WiFi radio as well as the cellular module. Current bitrates of the MangOH range of boards are low and there is not software written for them presently. The functionality of the Sierra Wireless Dev Kit PCB can be extended by using enabler boards that provide added functionality.
• Sierra Wireless Airlink end-user products have integrated WiFi and can be used as performance wireless routers.

Applications of the Sierra Wireless MC7455

The Sierra Wireless MC7455 wireless module for LTE Routers

The Sierra Wireless MC7455 is one of the most popular choices of a cellular modem for cellular routers, particularly those that are self or custom-built. It is compatible with most cellular carriers either by the carrier firmware or its proprietary generic version. As the routers rely on a cellular connection, they are cable-lite, have high mobility, and are a popular solution for RV living or field-use.

LTE routers use high-speed LTE connection for their internet connectivity which can then be distributed via 2.4 and 5 GHz WiFi (802.11ac) to client devices. With LTE routers, whether used for home networking or industrial applications, the router is reliant on the Sierra Wireless modem to connect to the cellular carrier and exchange data with the router.

The MC7455 is designed to be embedded on the PCB via a mini PCI-E slot. An active SIM card will need to be used by the modem to authorize access to the carrier network.

For an LTE router to function optimally, it will require a strong cellular signal. The performance of the router can be enhanced by the use of a suitable external antenna or cellular booster if the signal strength is poor or the location is remote. The antenna used must match the frequencies used by the cellular carrier. Broadband or multi-band cellular antennas are often preferable for these routers because they operate across a range of frequencies used by cellular carriers.

The Sierra Wireless MC7455 wireless module can provide cellular connectivity for M2M and IoT.

The size and technical specifications of the MC7455 wireless module make it advantageous as an embedded cellular modem in a range of Internet of Things (IoT) and machine-to-machine (M2M) applications. By being installed in objects, devices, and machinery, the module provides a wireless connection to the internet and GPS tracking, allowing the objects to be networked, monitored, and controlled remotely. IoT applications of this 4G M2M module include:

• Sierra Wireless MC7455 module for Public Safety

Agencies like law enforcement, fire, and emergency medical practitioners require in-field connectivity in challenging environments and evolving situations. Vehicle-based cellular routers are an agile solution for providing wireless connectivity for applications and devices that include land mobile radio, dashcams, and accessing criminal or medical records. Harnessing the cellular network is robust with reliable infrastructure and coverage assured, especially in urban areas. Cellular modems can also support personnel body-worn devices and e-ticketing machines.

• Sierra Wireless MC7455 module for Asset tracking

Wireless modules like the MC7455, which have GNSS functionality, are advantageous for solutions that require the location of assets. In combination with LTE, an embedded modem can be used for precision tracking of high-value assets across the globe. Objects of almost any size can be located quickly, saving time and manpower, with stick control and datasets that can be harnessed as business intelligence. Goods and cargo in transit can be monitored in real-time via cellular networks, with the connectivity and responsiveness needed to troubleshoot problems and adjust schedules where necessary.

• Sierra Wireless MC7455 module for Fleet monitoring

The haulage sector has been revolutionized by the use of cellular modules in a range of fleet management solutions. Embedded LTE modems provide Heavy Goods Vehicles with the connectivity to relay critical real-time information about the location and condition of vehicles and drivers. Fleet management software can then be used for fleet-wide oversight and communication with drivers where necessary. The use of LTE/GPS means that vehicles can be followed across the world with cost-efficient voice and video communication. Novel solutions developed with this technology include video-based pupillary monitoring for driver fatigue to assist in the prevention of accidents.

• Sierra Wireless MC7455 module for Industry

LTE is ideal for industrial IoT and M2M connectivity as it does not require the installation of cabling, meaning that connectivity can be sustained in harsh manufacturing, mining, or processing environments. Sensor and video-based systems can be used for remote monitoring of manufacturing processes with manual or automated interventions where necessary. This keeps personnel protected from the potential hazards of directly checking on industrial equipment or processes. LTE networking is also used to create building or campus-wide area Networks that can support building automation with integrated security and environmental controls.

• Sierra Wireless MC7455 module for Utilities

The widespread deployment of smart utility metering and integration of responsive renewable power necessitates a means of connectivity that is simple and can be readily expanded. The use of cellular networks particularly Low Power Wide Area Networking (LPWAN) for utilities, provides plug-and-play infrastructure that can support:

• Precision remote utility metering
• Real-time grid intelligence
• Integrated data management solutions.

By using LTE-based IoT solutions, utility companies can be far more responsive to power outages and locate specific outages quickly. Field workers can use LTE to communicate with their team, access information freely, and keep a contemporaneous record of their work. Fleets of service vehicles can also be remotely managed, optimizing their use across the utility network.

• Sierra Wireless MC7455 module for Infrastructure

Integration of the Internet of Things into the transport infrastructure and public spaces includes projects like responsive transport signage, connected buses and trains, and smart street lighting. Wastage is a big problem for conurbations with high population density and consumption. The use of cellular connectivity will enable the responsive management of essential services with prompt troubleshooting and targeted delivery of resources. Traffic and congestion can be tackled definitively by the use of signaling systems that can interact with vehicles via cellular vehicle to everything (C-V2X).

• Sierra Wireless MC7455 module for Retail

As online and store-based retail become more closely integrated, cellular modules have been used to develop solutions that facilitate retail transactions in any location. In particular, there is a demand for point-of-sale (PoS) technologies that are portable, secure, and easily scaled up as a business expands. LTE connectivity also delivers high-speed back-office functionality, with near-instant updating of stock control or automation of orders. LTE PoS terminals are reliable and can be used to provide business continuity in the event of a primary network failure. Enhanced connectivity in retail environments can be used for customized advertising or directing customers to offers and products that may be of interest to them.

• Sierra Wireless MC7455 module for Digital signage

Digital signal uses LCD or LED displays to project multimedia images that can be informational or advertising. This sector has become increasingly diverse with interactive and responsive solutions that harness high data LTE connectivity. Digital signage has previously used wired connections or WiFi, but cellular connectivity has proven to be more reliable, scalable, and cost-effective. Wireless LTE-driven digital signage is centrally managed but can be installed anywhere, meaning that targeted high-resolution campaigns can be run in public spaces, on transportation networks, or in arenas and malls.

Frequently Asked Questions for the Sierra Wireless MC7455 Cellular Modem

Does the Sierra Wireless MC7455 wireless card have 802.11 connectivity?

This is a cellular module with no Wi-Fi connectivity. It cannot be used to provide WiFi networking directly, though its cellular internet connection can be used in a router that also carries a WiFi card to allow client devices to connect wirelessly.

What is firmware?

Firmware is the software that provides default control for the cellular modem hardware. The MC7455 requires firmware for the operating environment necessary to execute its functions and interact with host device software. It is essential for the normal operation of the modem and should be regularly updated to maintain optimal performance and keep it secure. Cellular modems that are updated regularly have better performance and can take advantage of new features, interoperability, and functionality provided by the manufacturer as they are released.

Sierra Wireless cellular modules carry a Firmware Over-The-Air (FOTA) user module that enables them to be updated remotely. The modem uses its FOTA module to connect wirelessly to the proprietary servers that contain the firmware files. Alternatively, it may be possible to program the modem with other server credentials to install other software, though this must be executed carefully, or it will render the modem useless. Routers that carry the MC7455 must be actively connected to the internet to undertake regular FOTA user module checks or manually search for applicable updates.

What are the options for mc7455 firmware?

1] Pre-installed

The MC7455 modem can be used plug-and-play with the firmware that is installed. In the US the module carries four versions of the firmware in its Non-Volatile Random Access Memory (NVRAM). The firmware included are:

• Generic (this is the firmware that is published by Sierra Wireless)
• Sprint
• AT&T
• Verizon

The modem will use the most appropriate firmware for the SIM installed, loading and executing its function when the host device is powered on. The Sierra Wireless website carries firmware updates and release notes, as well as drivers for Windows, Linux, and Android.

2] Open WRT firmware

This is Linux-based open-source firmware that has been developed for a wide range of embedded devices. Open WRT is a writable file system that allows developers, engineers, and hobbyists to customize the firmware for modems used in a variety of applications. It has really opened up the market for self-built LTE routers. Several popular firmware programs for cellular routers or LTE routers have been written and packaged using Open WRT, including ROOTER, WiFiX, and GoldenOrb.

What are AT Commands?

Attention Commands are short text computing commands that are used to program a modem. They are used in devices like the Sierra Wireless MC7455 modem that use machine-to-machine communication to interact with the host device.

The command lines used all commence with ‘AT‘, which signifies attention from the MODEM. They are a subcategory of the Hayes commands that were developed in the 1980s to program a proprietary modem.

Cellular modems that use GSM, GPRS, and LTE use AT commands for their configuration, voice link, data link, and services like SMS and MMS.

AT commands are divided into four types:

• Test: this command is used to test the compatibility of certain commands with a specific modem.
• Read: this command retrieves the current setting being used by a cellular modem for its operation.
• Set: this AT command is used to program or set the operations of the cellular modem.
• Execution: These commands are used to execute operations with the modem to retrieve specific data or perform specific functions.

The correct use of AT commands is critical for preserving the functionality of a cellular modem. When programming a modem, it is vital to know exactly what a command will do to the modem and that it is compatible with the model of the modem being used. Programmers are advised to avoid using AT commands they are not certain of as they can “brick” the modem. Always fully study the manufacturer AT Command reference documentation.

What is a bricked modem?

This is a cellular modem or module that has been rendered useless by the improper use of AT Commands or upgrades. Though the device may be electronically functional, its programming has caused irretrievable errors.

Can the Dual SIM Single Standby function of this modem be used in routers with a single slot?

Though the Sierra Wireless MC7455 wireless modem has Dual SIM Single Standby switching, a large number of the LTE routers and other cellular devices it is compatible with only have a single SIM card slot.

To enable dual SIM functionality with the MC7455, a device would need to have a second slot integrated. This can be done by using:

• A Mini PCI-E to M.2 adapter with SIM slot or
• A Mini PCI-E to USB3.0 Adapter with SIM card slot

However, the modem would require software configuration to execute its dual SIM functionality and there is the additional issue of the host cellular devices firmware that would need to be compatible as the switching is firmware-driven.

Can I build my cellular router with the Sierra Wireless MC7455?

The MC7455 is a cellular wireless module of choice for self-build LTE routers. Specific techniques and products are beyond the scope of this article, but research via the leading LTE home networking forums and YouTube will yield a range of techniques and tutorials.

Can the MC7455 cellular module be used with Raspberry Pi?

The Sierra Wireless MC7455 cellular wireless module can be used with Raspberry Pi boards. Pi3 birds are often used with this modem. The Raspberry Pi can then use the MC7455 for wireless cellular connectivity. The module can be installed on a USB enabler board or PCIe to USB adapter board that can be inserted into the USB connector of the Raspberry Pi. The Pi will require the installation of OpenWRT firmware like GoldenOrb to use the cellular modem.

How can I improve my LTE cellular signal?

As cellular signal coverage is critical to the performance of this cellular module, it is essential to assess the available coverage of the carrier the cellular wireless device will be using. Information on the position of local cell towers can be researched online or obtained directly from the cellular carrier.

A poor cellular signal in the first instance can be remedied by the use of external antennas, often installed outdoors or high up inside a building with cabling run to the router. Mounting the external directional cellular antenna at height will help clear obstructions like dense vegetation. An outdoor LTE antenna should be pointed in the direction of the nearest suitable cell tower, with positional adjustments in accordance with the signal strength obtained.

Cellular boosters or repeaters can also be used with routers that carry the MC7455 module. These devices consist of a donor antenna, an indoor rebroadcasting antenna, and a signal amplifier that is designed to strengthen the cellular signal and minimize noise.

In Conclusion

The MC7455 cellular module is a versatile wireless card that has demonstrable applications and performance as a 4G/LTE modem. It is readily integrated into a range of devices, enabling them to utilize high-speed, high-throughput LTE networking for a range of consumer, commercial, and industry solutions.

To obtain the optimal performance of this cellular module, the attachment of the correct LTE and antennas, via quality U.FL to SMA pigtail adapters .

By using quality wireless modems like the MC7455 engineers, developers and consumers can take advantage of the convenience and reliability of Long Term Evolution.