Q: There is a space requirement for our application, which GSM/GPRS module is most suitable for it?
A: There are SIM300D/SIM340D with SMT (Surface Mount Technology) which could meet your space requirement.

Q: What's the Tri-Band and Quad-Band in GSM/GPRS System?
A: Tri-Band: 900/1800/1900MHz
Quad-Band: 850/900/1800/1900MHz
Most GSM networks operate in the 900 MHz or 1800 MHz bands. Some countries in the Americas (including Canada and the United States) use the 850 MHz and 1900 MHz bands because the 900 and 1800 MHz frequency bands were already allocated.

Q: What are GSM, GPRS and EDGE?
A: GSM (Global System for Mobile communications) is an open, digital cellular technology used for transmitting mobile voice and data services. GSM differs from first generation wireless systems in that it uses digital technology and time division multiple access transmission methods

GPRS (General Packet Radio Service) is the world’s most ubiquitous wireless data service, available now with almost every GSM network. GPRS is a connectivity solution based on Internet

Protocols that supports a wide range of enterprise and consumer applications.
Further enhancements to GSM networks are provided by Enhanced Data rates for GSM Evolution (EDGE) technology. EDGE provides up to three times the data capacity of GPRS.

Any further information please visit at

Q: What's the SIMCOM wireless modules?
A: Shanghai SIMCOM Wireless Solutions Ltd, a subsidiary of SIM Technology (HK:2000), provided wireless module and customized solution for customers, targeting for different applications like WLL, M2M, mobile computing and handheld devices on GSM/GPRS/EDGE, WCDMA/HSDPA, TD-SCDMA, WiFi and GPS technology. SIMCOM® is currently the number 1 provider of wireless modules in Asia and Number 3 in the world. The product philosophy of SIMCOM is making the solution simple, low-cost but enough features and performance.

Q: What is the SIMCOM product line for GSM/GPRS wireless modules?
A: 1. 3-3.5G Module Solution
SIM4000 - TD-SCDMA Solution,
SIM5210 - WCDMA/HSDPA Solution

2. GSM/GPRS/EDGE Module Solution
SIM600 - Quad-Band Solution

3. GSM/GPRS+GPS Module Solution
SIM508 - Tri-Band Solution
SIM548 - Quad-Band Solution

4. GSM/GPRS Module Solution
SIM300, SIM300C, SIM300D - Tri-Band Solution
SIM340, SIM340C, SIM340D - Quad-Band Solution

Q: How many applications are SIMCOM wireless modules used to?
A: There are more and more applications based on wireless modules with the development of mobile technology, including but not limited in AVL(Automatic Vehicle Location), Telematics, Metering, Remote Monitoring, Fleet Management, Vending Machine, security etc.

Q: I would like to integrate SIMCOM wireless module into the Vehicle Tracking System in our ongoing project, could you please give me any suggestion on GSM/GPRS module selection?
A: We would like to recommend SIM300C/SIM340C with DIP BTB connector for Vehicle Tracking System. Or if there is much more space requirement in your application, SIM300D/SIM340D with SMT (Surface Mount Technology) could be considered.

Q: What's the GPS technology?
A: The Global Positioning System (GPS) is the only fully functional Global Navigation Satellite System (GNSS). Utilizing a constellation of at least 24 medium Earth orbit satellites that transmit precise microwave signals, the system enables a GPS receiver to determine its location, speed and direction.

Q: We have a design combined GSM/GPRS with GPS technology. Could you please let us know which is the best solution based on SIMCOM module?
A: There are two kinds of GSM/GPRS wireless modules integrated in GPS function
SIM508 - Tri-Band GSM/GPRS+GPS wireless Module
SIM548 - Quad-Band GSM/GPRS+GPS wireless Module

Q: I am wondering where I could get all the accessories for our ongoing project based on SIMCOM wireless modules?
A: M2Mcom Ltd. is a Global-Provider of wireless communications applications with a wide range of fully integrated modules, accessories and solutions. Our customers could expect that they get all the accessories from us.

Q: One table says that the peak current in transmit mode can be 2A every 4.6ms. What mode is that in? Most of the other table entries say that the power is 300mA or less (23mA for idle mode).
A: When the module is in TALK mode, the peak current is 2A every 4.6ms. 300mA (23mA for IDLE mode) means average current in the mode. When being sending SMS, the module should be in TALK mode (CSD), so the maximum current is 2A.

Q: Do you have any other question?
A: Please send your question to us .You will get our reply as soon as possible.

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GSM - Global System for Mobile Communications
The pan-European digital cellular system standard (developed by a committee of European telecommunications administrators, operators, and manufacturers), now deployed worldwide at 900 MHz and gaining popularity at 1800 and 1900 MHz. Defines a radio interface based on 8-user time division multiple access (TDMA) with 200-kHz channel spacing and advanced features. Formerly it was called Groupe Speciale Mobile.

GPRS - General Packet Radio Service
A Global System for Mobile Communications (GSM) initiative to deliver high speed packet data services to mobile terminals. GPRS allows many users to share the same channel and allows users to stay virtually 'on line' all of the time; radio resources are used only when data is actually being transmitted or received. Call setup is almost instantaneous and users may be charged on the basis of actual data transmitted, rather than connection time. Sometimes it is defined as GSM Packet Radio Service.

EDGE - Enhanced Data rate for Global Evolution
A technology (also known as GSM++) that allows Global System for Mobile Communications (GSM) operators to use existing GSM radio bands to offer wireless multimedia IP-based services and applications at speeds of 384 kbps with a bit-rate of 48 kbps per timeslot and up to 69.2 kbps per timeslot under ideal radio conditions. (A more realistic theoretical limit is 59.2 kbps per timeslot). The 384 kbps prediction is from an International Telecommunication Union (ITU)-defined objective in the ITU2000 standard. EDGE is fully based on GSM and requires relatively small changes to network hardware and software. For example, EDGE uses the same time division multiple access (TDMA) frame structure, logic channel, and 200-kHz carrier bandwidth as today's GSM networks, allowing existing cell plans to remain intact. Formerly was called Enhanced Data rate for GSM Evolution.

3G is the term given to the next generation of mobile communication systems. These offer enhanced services, such as multimedia and video. The main 3G technologies include UMTS and CDMA2000. 3G was an initiative originally spearheaded by the ITU (International Telecommunications Union) under the IMT2000 project.

UMTS - Universal Mobile Telecommunications System
A name the European Telecommunication Standards Institute (ETSI) uses to describe a third-generation (3G) technology that offers services to mobile computer and phone users anywhere in the world. Based on the Global System for Mobile (GSM) communication standard, UMTS is the planned standard for mobile users around the world. UMTS, fully implemented, gives computer and phone users access to the Internet as they travel. They have the same capabilities even when they roam, through both terrestrial wireless and satellite transmissions.

HSDPA - High-Speed Downlink Packet Access

An upgrade for WCDMA / UMTS networks. It doubles network capacity and increases download data speeds five-fold or more. HSDPA is standardized by the 3GPP in UMTS Release 5.

Wi-Fi - Wireless Fidelity
Wi-Fi is used as the global brand name across all markets for any 802.11-based (Ethernet) wireless LAN products. Typically any Wi-Fi product using the same radio frequency (for example, 2.4GHz for 802.11b or 11g, 5GHz for 802.11a) are interoperable.

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Abbreviation Description
ADC Analogue-to-Digital Converter
ARP Antenna Reference Point
BER Bit Error Rate
BTS Base Transceiver Station
CS Coding Scheme
CSD Circuit Switched Data
CTS Clear to Send
DAC Digital-to-Analogue Converter
DRX Discontinuous Reception
DSP Digital Signal Processor
DTE Data Terminal Equipment (typically computer, terminal, printer)
DTR Data Terminal Ready
DTX Discontinuous Transmission
EFR Enhanced Full Rate
EGSM Enhanced GSM
EMC Electromagnetic Compatibility
ESD Electrostatic Discharge
ETS European Telecommunication Standard
FCC Federal Communications Commission (U.S.)
FDMA Frequency Division Multiple Access
FR Full Rate
GMSK Gaussian Minimum Shift Keying
GPRS General Packet Radio Service
GSM Global Standard for Mobile Communications
HR Half Rate
IMEI International Mobile Equipment Identity
Inorm Normal Current
Imax Maximum Load Current
kbps Kilo bits per second
Li-Ion Lithium-Ion
MO Mobile Originated
MS Mobile Station (GSM engine), also referred to as TE
MT Mobile Terminated
PAP Password Authentication Protocol
PBCCH Packet Switched Broadcast Control Channel
PCB Printed Circuit Board
PCS Personal Communication System, also referred to as GSM 1900
RF Radio Frequency
RMS Root Mean Square (value)
RTC Real Time Clock
Rx Receive Direction
SIM Subscriber Identification Module
SMS Short Message Service
TDMA Time Division Multiple Access
TE Terminal Equipment, also referred to as DTE
TX Transmit Direction
UART Universal Asynchronous Receiver & Transmitter
VSWR Voltage Standing Wave Ratio
Vmax Maximum Voltage Value
Vnorm Normal Voltage Value
Vmin Minimum Voltage Value
VIHmax Maximum Input High Level Voltage Value
VIHmin Minimum Input High Level Voltage Value
VILmax Maximum Input Low Level Voltage Value
VILmin Minimum Input Low Level Voltage Value
VImax Absolute Maximum Input Voltage Value
VImin Absolute Minimum Input Voltage Value
VOHmax Maximum Output High Level Voltage Value
VOHmin Minimum Output High Level Voltage Value
VOLmax Maximum Output Low Level Voltage Value
VOLmin Minimum Output Low Level Voltage Value
FD SIM fix dialling phonebook
SM SIM phonebook
NC Not connect
EDGE Enhanced data rates for GSM evolution
HSDPA High Speed Downlink Packet Access
ZIF Zero intermediate frequency
WCDMA Wideband Code Division Multiple Access
VCTCXO Voltage control temperature-compensated crystal oscillator
USIM Universal subscriber identity module
UMTS Universal mobile telecommunications system
UART Universal asynchronous receiver transmitter

Abbreviation Description
ATP Adaptive Trickle Power mode.
DGPS Differential GPS
GGA GPS Fixed Data
GPS Global Positioning System
LNA Low Noise Amplifier
RTCM Radio Technical Commission for Maritime Services

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Please send your additional questions to us!

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All products sold were come with one year limited warranty. Please send the product IMEI number to us.

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GSM standard documentations

SN Document name Remark
[1] ITU-T Draft new recommendation V.25ter: Serial asynchronous automatic dialling and control
[2] GSM 07.07: Digital cellular telecommunications (Phase 2+); AT command set for GSM Mobile Equipment (ME)
[3] GSM 07.10: Support GSM 07.10 multiplexing protocol
[4] GSM 07.05: Digital cellular telecommunications (Phase 2+); Use of Data Terminal Equipment – Data Circuit terminating Equipment (DTE – DCE) interface for Short Message Service (SMS) and Cell Broadcast Service (CBS)
[5] GSM 11.14: Digital cellular telecommunications system (Phase 2+); Specification of the SIM Application Toolkit for the Subscriber Identity Module – Mobile Equipment (SIM – ME) interface
[6] GSM 11.11: Digital cellular telecommunications system (Phase 2+); Specification of the Subscriber Identity Module – Mobile Equipment (SIM – ME) interface
[7] GSM 03.38: Digital cellular telecommunications system (Phase 2+); Alphabets and language-specific information
[8] GSM 11.10 Digital cellular telecommunications system (Phase 2); Mobile Station (MS) conformance specification; Part 1: Conformance specification

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