Hardware

Figure : 4G module

Specifications

The 4G module is based on the LE910 chipset, manufactured by Telit. The module is managed by UART and it must be connected to socket 1 (direct connection, without Expansion Board). The main features of the module are listed below:

• Output power:

  • Class 4 (2 W, 33 dBm) @ GSM 850 / 900

  • Class 1 (1 W, 30 dBm) @ GSM 1800 / 1900

  • Class E2 (0.5 W, 27 dBm) @ EDGE 850 / 900

  • Class E2 (0.4 W, 26 dBm) @ EDGE 1800 /1900

  • Class 3 (0.25 W, 24 dBm) @ UMTS

  • Class 3 (0.2 W, 23 dBm) @ LTE

• Data transmission:

  • LTE:

    • Uplink up to 50 Mbps

    • Downlink up to 100 Mbps

  • HSPA+:

    • Uplink up to 5.76 Mbps

    • Downlink up to 42.0 Mbps

  • UMTS:

    • Uplink/Downlink up to 384 kbps

• Protocols:

  • TCP/UDP

  • HTTP

  • FTP

Versions

Telit has different versions of the LE910 chipset. Each one of them was especially designed to comply with the RF and cellular regulations in different countries or regions of the world. Libelium originally integrated the following versions:

Features	LE910 EUG (v1)	LE910 NAG (v1)	LE910 AU V2
Region	Europe and Brazil	USA and Canada (Americas)	Australia
Supported 4G bands	B20 (800) B3 (1800) B7 (2600)	B17 (700) B5 (850) B4 (1700) B2 (1900)	B3 (1800) B7 (2600) B28 (700)
3G fall-back	Yes	Yes	No
Supported 3G bands	B5 (850) B8 (900) B1 (2100)	B5 (850) B2 (1900)	None
2G fall-back	Yes	Yes	No
Supported 2G bands	GSM 900, DCS 1800	GSM 850, PCS 1900	None
GPS/GLONASS	Yes	Yes	No
Certifications	CE (R&TTE), GCF	FCC, IC, PTCRB, AT&T	RCM, Telstra
Availability	Discontinued on November 2019	Discontinued on April 2019	Yes

Important note: The current stock of the LE910 4G radio that the manufacturer 'Telit' is distributing comprises the v2 version which does not have GPS. The models are:

• LE910-EU V2 for Europe or Brazil

• LE910-NA V2 for US or Canada

• From April 2019, Libelium only offers the LE910 NA V2 for USA and Canada, since Telit discontinued the original LE910 NAG.

• From November 2019, Libelium only offers the LE910 EU V2 for Europe and Brazil, since Telit discontinued the original LE910 EUG.

These v2 radios are similar to the v1 ones, but support more bands and do not have a GPS receiver.

Features	LE910 EU V2	LE910 NA V2
Region	Europe	USA and Canada (Americas)
Supported 4G bands	B20 (800) B8 (900) B3 (1800) B1 (2100) B7 (2600)	B12 (700) B13 (700) B5 (850) B4 (1700) B2 (1900)
3G fall-back	Yes	Yes
Supported 3G bands	B8 (900) B1 (2100)	B5 (850) B2 (1900)
2G fall-back	Yes	No
Supported 2G bands	900 /1800	None
GPS/GLONASS	No	No

How to connect the module

This module must be connected to the SOCKET1 on the Waspmote board. Like any other cellular radio, the connection is native so the radio does not need the Expansion Radio Board.

Figure : Module connected to Waspmote in SOCKET1

The SIM card used in the 4G module OEM version is a “standard SIM”, also known as “mini SIM”. The next picture shows how the SIM card must be plugged in the 4G module.

Figure : SIM card installation in OEM version

On the other hand, Plug and Sense! models with 4G radio provide a special connector in order to plug both micro USB wire and nano SIM card for the 4G module.

Figure : SIM card installation in Plug and Sense! version

Figure : Push-push mechanism in the External SIM/USB socket

Antennas

The 4G module comes with 2 cellular antennas for improving the signal reception: normal (main) antenna and diversity antenna.

All these antennas are the same model and can be used in any of the 4G sockets. The operating bands of the dipole antenna go from 698 to 960 MHz and from 1710 to 2690 MHz. The maximum gain of the antenna is observed at 2.6 GHz: 3.4 dBi.

To get the maximum performance, it is recommended to place the antennas like that:

• The main cellular antenna should be in vertical position, pointing to the sky, in order to radiate better to the cellular base stations around.

• The diversity cellular antenna should be in horizontal position (orthogonal, 90º, to the main antenna). Besides, the plane where the antenna is should be also orthogonal to the main antenna's plain. Finally, it is advised to place this 2nd cellular antenna as far as possible from the main antenna. These 3 measures will maximize the gain due to reception diversity.

Figure : 4G module antennas

Power consumption

The 4G module is directly powered by the battery. The next table shows the Waspmote's peak current consumption in different states of the 4G module.

State	Mean power consumption
On	100 mA
Transmitting data	400 mA
Receiving data	400 mA

Non-rechargeable batteries are not advised for the 4G module, because the high peaks of current consumption could make the voltage of these batteries to go below 3.3 V so Waspmote would reset. The rechargeable battery will not suffer this effect as long as its level is above 20%.

Time consumption

The following table describes the mean elapsed time for some actions in a single test for several attempts:

Action	Mean elapsed time
Power on	~11 s
Start data connection	~4 s
Perform HTTP GET or POST	~0.7 s
Open FTP session	~3 s
Perform FTP upload 10 kB file	~7 s
Perform FTP download 10 kB file	~6 s

Some of these actions approximately have a fixed elapsed time like powering on the module. However, the actions related to data transmission (HTTP, FTP, etc.) are dependent on external circumstances (MNO, coverage quality, etc) and show more variability from the mean value.