JioFi 4 is a personal hotspot from Reliance and is the most portable router I have come across. The main advantage of it is its portability: you can carry it anywhere you go. It is a very tiny but a powerful device.
On the connectivity part, I will say it gives you an average speed ( not like fastening light speed) . Tried using the connection on my smart phone and the connectivity remained constant. No buffering issue on you tube videos and some live trivia games; though the speedtest shows a disappointing 3.45 mbps for downloading and 0.50 mbps for uploading. However, the speed may also vary depending on the user’s location.
Positive thing about the device is, it can let you connect up to 31 devices ( so it claims) . Also, it enables HD voice and video call on any smartphone ( yet to try this feature) . With 2600 mAh battery, it gives you a standby time of approximately 480 hours and a running time of 7 to 8 hours, depending on network conditions ofcourse.
It should be noted that the JioFi device works only with Jio SIM, which needs to be installed before using it. To conclude it is a tiny little device with great portability but still needs improvement in terms of speed.