LTE: It's in the Ads. It's in the News. But What Exactly is LTE?

LTE INFOGRAPHIC SERIES LTE: It's in ads. It's in the news. ROOT Metrics® But what exactly is LTE? LTE (Long Term Evolution) is the newest, fastest mobile network technology available. Read on to see how LTE is put together and how it can impact your mobile experience. It starts with spectrum SPECTRUM ALLOCATION The U.S. government reserves different frequencies of the spectrum for different uses. Spectrum is the range of electromagnetic radio frequencies used to transmit sound and data through the air. Spectrum is limited and is the carrier's most 27.2% 26.7% 17.1% 15.0% 14.0% Defense Other comm. Aero Mobile Other valuable resource. SPECTRAL EFFICIENCY Cell phone activity occurs between 700 MHz and 2.5 GHz 3G 700 MHz 2.5 GHz LTE LTE squeezes more bits per second from fewer hertz of frequency. Why it matters: Greater efficiency means more capacity on a given bandwidth, which means a network can handle a greater amount of traffic. How engineers build an LTE network LTE can be set up in one of two ways: TDD or FDD. TDD (TIME DIVISION DUPLEX) Different slices of time on the same frequency block are assigned for downlink and uplink activity. Currently used in China. U.S. carriers could adopt in the future. TDD CHHHHOHHHHKHHH (Unpaired) FDD (Paired) CHKHOHHKKH040HHHOHOHOH I Download D Upload FDD (FREQUENCY DIVISION DUPLEX) Paired spectrum channels are created from the available bandwidth. One channel is devoted to downlink and one to uplink. Used in the U.S. LTE IS Flexible There are different LTE configurations depending on the 1.4, 3, 5, 10, 15, or 20 MHz spectrum bandwidth a carrier has available. 5 +5 CONFIG 10 + 10 CONFIG 20 + 20 CONFIG Carriers deploy LTE in different frequency bandwidths. This allows flexibilty, but means LTE networks are not equal. 10 MHz 20 MHz 40 MHz 5 for uplink 10 for uplink 20 for uplink 5 for downlink 10 for downlink 20 for downlink Bigger channels mean more capacity. Why it matters: More capacity means less congestion and faster speeds. When a cell tower's signal overlaps How far a frequency can travel and how well it can penetrate solid objects. with another signal, noise is created. Why it matters: Better propagation = better indoor coverage. PROPAGATION NOISE Why it matters: More noise = more service problems. Low frequencies High frequencies Travel far and penetrate solids better. Don't travel as far or penetrate solids as well. PROPAGATION: EXCELLENT PROPAGATION: POOR NOISE: LOW Smaller areas of signal overlap mean less noise. Adding more towers to increase NOISE: HIGH capacity = not as susceptible to noise. More noise possible due to larger areas of signal overlap. Adding towers to handle HI capacity could increase disruptions. LTE IS More efficient RADIO NETWORK MIMO (Multiple Input, Multiple Output) CONTROLLER (RNC) MIMO refers to multiple antennas used at both the tower The RNC coordinates and device. This improves the link and offers better communication (handovers, power coverage and increased transmission speed. control, security, etc.) between the base station and network. RNC In 3G networks, RNC is a separate element from the base station. MIMO CONFIGS RNC RNC RNC LTE streamlines this process with the base-band unit taking over most of RNC functionality. 4 x 4 Not currently used. No device support yet. 2 x 2 4 x 2 T-Mobile might be first to implement.' Most common LTE Why it matters: A simpler, cheaper, config right now. and more efficient all-IP flat network architecture. LTE is not created equal Carriers put these LTE building blocks together differently and this contributes to differences in LTE performance. Why it matters: Just because you have LTE doesn't mean you're guaranteed top-line performance. AT&T Sprint T-Mobile Verizon Currently uses a 5 + 5 MHz configuration. SPECTRUM 10 + 10 MHz A mix of 5 + 5 MHz 10 + 10 MHz ALLOCATION configuration in most markets (5 + 5 where and 10 + 10 MHz configuration across (depends on the all markets. spectrum is limited). spectrum available in each market). FREQUENCY 700 MHz as the core, 1900 MHz PCS band. AWS (1700/2100 MHz). 700 MHz as the core, BAND USED with AWS (1700/2100 Will launch 800 MHz with AWS (1700/2100 MHz) available in LTE in 2014. MHz) available in some areas. some areas. +19.0 / 19.1 +7.4 / 13.5 +16.6 / 110.1 +14.9 / 18.3 AVERAGE LTE SPEEDS? Mbps LTE IS Fast What can you do with these speeds?" STREAM TUNES STREAM HD MOVIE EMAIL A PICTURE 128 Kbps 1.5-4 Mbps З МВ 20+ Mbps Instant start 5 sec buffer 1 second No interruptions No interruptions 10-20 Mbps 1 sec buffer 30 sec buffer 5 seconds No interruptions No interruptions 6-10 Mbps 1 sec buffer 1 min buffer 5 seconds No interruptions Some interruptions 3-6 Mbps 5 sec buffer 2 min buffer 10 seconds No interruptions Several interruptions 1 Goldstein, Phil. "Report: T-Mobile to use 4x2 MIMO to boost LTE network performance." Accessed September 24, 2013. http://rtmet.com/1dMkoKT 2 Averages based on RootMetrics testing during the first half of 2013. 3 The examples showing what data speeds mean while performing various mobile activities are general guidelines for illustrative purposes, and do not represent performance in a specific market. Consumers might not find these exact numbers while performing the activities within this report because speeds can vary depending on a variety of factors including, but not limited to: network conditions, backhaul, provisioning, whether a consumer is indoors or outdoors, the "noise" of other activity near the tower, network technologies available, the mobile device used, and environmental or topographical variables, O RootMetrics 2013. All rights reserved.