The TP Link TL-MR3040 Portable Battery Powered 3G/4G Wireless N Router doesn't work out of the box with the Airtel 4G dongle (specifically Huawei E3272).
But help is at hand!
An updated firmware (albeit beta) gets it working.
Here's the link https://hc6800em.wordpress.com/2015/03/08/router-tl-mr3040-com-modem-vivo-huawei-e3272/ (choose the beta file from Option1: http://www.tplink.com/resources/software/_beta_TL-MR3040V2_140827_solve_WISP_can_t_connect_TrueWiFi_hotspoy_iPhone_isue.zip).
And here's how you update the firmware: http://www.tp-link.com/en/faq-688.html
Oh! And if you don't comprehend Portuguese, Google Translate is your friend :-)
But help is at hand!
An updated firmware (albeit beta) gets it working.
Here's the link https://hc6800em.wordpress.com/2015/03/08/router-tl-mr3040-com-modem-vivo-huawei-e3272/ (choose the beta file from Option1: http://www.tplink.com/resources/software/_beta_TL-MR3040V2_140827_solve_WISP_can_t_connect_TrueWiFi_hotspoy_iPhone_isue.zip).
And here's how you update the firmware: http://www.tp-link.com/en/faq-688.html
Oh! And if you don't comprehend Portuguese, Google Translate is your friend :-)