4g means (Fourth Generation Cellular Technology) , first introduced in 2011, The high data transfer rates make 4G networks suitable for use in USB wireless modems for laptops and even home internet access. 4g network service started in Bangladesh 2018 , telecommunications and information technology minister Mustafa Jabbar handed over the licenses to state-owned Teletalk, Banglalink, Grameenphone and Robi. According to ITU Radio Regulation and NFAP, 698 – 806 MHz, 2500 – 2690 MHz and 1920 -1980 / 2110-2170 MHz frequency bands are reserved for 3G/ 4G/ LTE services. Inorder to materialize the dream 'Digital Bangladesh', and to implement ’Vision 2021’ it is necessary to make voice and data service make available at the door step of general people. 3G/ 4G/ LTE are the means to make voice and data service available to distant population of the country. In this regard 3G frequency has already been assigned to the state owned GSM operator Teletalk 4G using IMT-Advanced (International Mobile Telecommunications Advanced), as defined by ITU-R. An IMT-Advanced cellular system must fulfill the following requirements:
1) Be based on an all-IP packet switched network.2) Have peak data rates of up to approximately 100 Mbit/s for high mobility such as mobile access and up to approximately 1 Gbit/s for low mobility such as nomadic/local wireless access.3) Be able to dynamically share and use the network resources to support more simultaneous users per cell.4) Use scalable channel bandwidths of 5–20 MHz, optionally up to 40 MHz.5) Have peak link spectral efficiency of 15-bit/s/Hz in the downlink, and 6.75-bit/s/Hz in the up link (meaning that 1 Gbit/s in the downlink should be possible over less than 67 MHz bandwidth).6) System spectral efficiency is, in indoor cases, 3-bit/s/Hz/cell for downlink and 2.25-bit/s/Hz/cell for up link.7) Smooth handovers across heterogeneous networks.
4g mobile network in Bangladesh