# Does LX40 requires cellular antenna connected in order to work/sent out SMS?

**URL:** <https://forum.sierrawireless.com/t/does-lx40-requires-cellular-antenna-connected-in-order-to-work-sent-out-sms/29237>\
**Category:** AirLink routers\
**Created:** [March 13, 2023, 8:28am UTC](https://forum.sierrawireless.com/t/does-lx40-requires-cellular-antenna-connected-in-order-to-work-sent-out-sms/29237 "2023-03-13T08:28:00Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![cheng.yin](https://avatars.discourse-cdn.com/v4/letter/c/58f4c7/32.png) [@cheng.yin](https://forum.sierrawireless.com/u/cheng.yin)\
**Post date:** [March 13, 2023, 8:28am UTC](https://forum.sierrawireless.com/t/does-lx40-requires-cellular-antenna-connected-in-order-to-work-sent-out-sms/29237/1 "2023-03-13T08:28:00Z")

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Hi All, im new to AirLink devices. Right now i am testing a LX40 with a prepaid SIM(with 4G and SMS function available) card, hoping to send out some alarm sms.  
But there seems to be no connection (flashing red light for Network and Signal). In the box that i have received, there is no antenna provided. Are we supposed to get an external antenna on our own?..

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**Author:** ![jerdung](https://avatars.discourse-cdn.com/v4/letter/j/82dd89/32.png) [@jerdung](https://forum.sierrawireless.com/u/jerdung)\
**Post date:** [March 15, 2023, 8:03am UTC](https://forum.sierrawireless.com/t/does-lx40-requires-cellular-antenna-connected-in-order-to-work-sent-out-sms/29237/2 "2023-03-15T08:03:01Z")

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Hi @cheng.yin  
Welcome you to our community!  
For connect to LTE network, you must have two external antennas connected to your LX40 Airlink. For more details, please refer to Section 2 - Installation and Startup on page 18 in the link below:  
[https://source.sierrawireless.com/resources/airlink/hardware\_reference\_docs/airlink\_lx40\_userguide/#sthash.vvmlFtus.dpbs](https://source.sierrawireless.com/resources/airlink/hardware_reference_docs/airlink_lx40_userguide/#sthash.vvmlFtus.dpbs)

Thanks

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**Author:** ![cheng.yin](https://avatars.discourse-cdn.com/v4/letter/c/58f4c7/32.png) [@cheng.yin](https://forum.sierrawireless.com/u/cheng.yin)\
**Post date:** [March 15, 2023, 8:14am UTC](https://forum.sierrawireless.com/t/does-lx40-requires-cellular-antenna-connected-in-order-to-work-sent-out-sms/29237/3 "2023-03-15T08:14:38Z")

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Hi Jerdung, thank you for replying. For the antenna, is there a specific type, or any general antenna will do?

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**Author:** ![jerdung](https://avatars.discourse-cdn.com/v4/letter/j/82dd89/32.png) [@jerdung](https://forum.sierrawireless.com/u/jerdung)\
**Post date:** [March 20, 2023, 7:29am UTC](https://forum.sierrawireless.com/t/does-lx40-requires-cellular-antenna-connected-in-order-to-work-sent-out-sms/29237/4 "2023-03-20T07:29:50Z")

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Hi @cheng.yin  
About the antenna for LX40 Airlink, please refer to the document in the link below:

> **[SW-Datasheet-Antenna-PaddleCell-Aug2022.pdf](https://www.sierrawireless.com/wp-content/uploads/2022/08/SW-Datasheet-Antenna-PaddleCell-Aug2022.pdf)**
>
> 90.57 KB

Thanks,

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**Author:** ![cheng.yin](https://avatars.discourse-cdn.com/v4/letter/c/58f4c7/32.png) [@cheng.yin](https://forum.sierrawireless.com/u/cheng.yin)\
**Post date:** [March 20, 2023, 11:10am UTC](https://forum.sierrawireless.com/t/does-lx40-requires-cellular-antenna-connected-in-order-to-work-sent-out-sms/29237/5 "2023-03-20T11:10:10Z")

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Hi jerdung, thank you for replying.  
Actually right now my route is communication (able to send out alarm sms from Ignition)  
However, i have looked through all those sample settings done by others and applied the same, but i am able to acknowledge the alarm by sending back a sms text.

Is there anything i need to look out for?

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**Author:** ![jerdung](https://avatars.discourse-cdn.com/v4/letter/j/82dd89/32.png) [@jerdung](https://forum.sierrawireless.com/u/jerdung)\
**Post date:** [March 29, 2023, 8:19am UTC](https://forum.sierrawireless.com/t/does-lx40-requires-cellular-antenna-connected-in-order-to-work-sent-out-sms/29237/6 "2023-03-29T08:19:32Z")

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Hi @cheng.yin  
For your request, please refer to Section 10 - Events Reporting Configuration on page 285 in the link below:  
[https://source.sierrawireless.com/resources/airlink/software\_reference\_docs/airlink-lx40---configuration-guide/#sthash.tmZr0Gcs.dpbs](https://source.sierrawireless.com/resources/airlink/software_reference_docs/airlink-lx40---configuration-guide/#sthash.tmZr0Gcs.dpbs)

Thanks,