ectral efficiency evolution for user equipment with two antennas is illustrated in Figure 3.1 showing the relative difference between HSPA Release 6, HSPA+ and LTE. These examples show the gains that can be achieved from increasing the granularity of the scheduling. The scheduling algorithms in an e node B will be different to the scheduling algorithms used in a microcell or macrocell. In larger cells round-trip signalling delay means that the shorter scheduling options (for example half millisecond) cannot be used. Also, in the lower Making Telecoms Work Downlink Uplink HSPA Release 6 HSPA+ Figure 3.1 Evolution of spectral efficiency. Reproduced with permission of Nokia Siemens Networks. bands it is unlikely that the 20-MHz channel bandwidths used to get high peak data rates in WiFi or higher-band LTE networks could be deployed. This is not a problem but a function of fundamental channel properties at different frequencies. Note that channel-sensitive scheduling does not deliver gain in larger cells or for users moving at faster than walking pace. Fast-moving users become part of the multichannel averaging process as they move through the continuously changing multipath channel. The point about LTE is that it has been designed to be flexible enough at the physical layer to scale across a wide range of channel bandwidths and respond to a wide range of channel conditions. The ability to support 1.4 MHz, 3 MHz and 5 MHz, 10, 15 and 20 MHz channel spacing is one example. This should deliver substantial throughput gains. However, we have said that LTE must also deliver more efficient throughput in terms of joules per bit and/or megabytes per watt hour both at the e node B and the user device (to extend the user data duty cycle) and in small cells and large cells and for stationary users and highly mobile users (potentially up to 500 kph and certainly 350 kph). We have stated that scheduling at the physical layer in small cells can be in one-millisecond increments and/or across different OFDMA subcarriers in the frequ