or 3.0 MHz is to perform spectral refarming, wherein the operator can maximize the global system for mobile communications (GSM) spectrum by refarming to LTE. Operators can refarm using a much narrower spectrum than before and deliver GSM and wideband code division multiple access (WCDMA) with less spectrum and also lower total cost of ownership. Moreover, they can deliver a vastly improved user experience and potentially attract more customers to increase revenues. Larger bandwidths of 10 MHz, 20 MHz, or more are used to provide higher data rates in a network. TDD VS. FDD This section compares TDD and FDD, and we will stick to the differences for these modes purely from an operational and implementation (deployment) point of view. However, the two modes of LTE have many more differences when compared from an architectural, designing, and testing point of view. A few differences that are seen between TDD and FDD are: In LTE TDD mode, there is no concept of a paired spectrum. This also means that in any given instance, the eNodeB or the UE will be involved only in transmission or reception of the data, but never both. For a TDD setup, the hardware design is much simpler, because at any given time, there is either transmission or reception happening, but not both. In other words, there is no need for a duplexer to have an isolated UL/DL path on the receiver/transmitter implementation for an LTE TDD device (UE/eNodeB). This also makes the equipment a little less expensive. Because there is no difference in frequency for UL and DL for LTE TDD, the channel estimation or path loss calculation in both directions is similar. This eases the link budget planning activity. This also means that the channel estimation can be more robust in LTE TDD under load conditions and fast-fading conditions wherein the eNodeB need not always rely on UE reported channel feedback for corrective actions. A large guard period is required for the eNodeB to switch from DL transmission to UL transmission. This results in a drop in efficiency an