LTE vs. WiMAX
The argument between LTE and WiMAX continues to rage at least three years after it ignited. Though many, except for Sprint and Clearwire, think it might already be over, with LTE the winner.
A few years ago, it seemed mobile WiMAX was on the fast track to be the 4G wireless technology of choice for evolving mobile broadband networks. Sprint put a stake in the ground, committing $5 billion to be the first in the industry by two years to offer a 4G mobile broadband network. Cisco bought Navini Networks for more than $300 million to produce mobile WiMAX radio access network equipment, and Sprint and Clearwire formed a $14.5 billion venture to combine mobile WiMAX operations into a new company.
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But late in 2007, the two biggest carriers in North America, Verizon and AT&T, said they would adopt Long Term Evolution (LTE), viewed as a competing technology to mobile WiMAX, as the underpinning of their 4G networks. Both carriers said LTE provides a more natural upgrade for their GSM/UMTS/HSPA/CDMA-based networks and subscribers – and GSM is the dominant mobile standard worldwide, with more the 3 billion global customers as of February 2010.
The rug had been pulled out from under mobile WiMAX.
Both wireless technologies are intended to offer ubiquitous broadband at multiple megabits per second. Mobile WiMAX is an IEEE specification also known as 802.16e and designed to support as high as 12Mbps data-transmission speeds. It uses Orthogonal Frequency Division Multiple Access, which transmits data by splitting radio signals that are broadcast simultaneously over different frequencies. These signals are immune to interference and can support high data rates.
LTE was developed in the Third-Generation Partnership Project as the natural progression of High-Speed Packet Access (HSPA), the GSM technology that is currently used by carriers such as AT&T to deliver 3G mobile broadband. LTE is a modulation technique that is designed to deliver 100Mbps per channel and give individual users performance comparable to today's wired broadband.
But as events have unfolded, it appears as if mobile WiMAX has lost momentum in the 4G race. Not only did the two largest wireless operators in North America and the GSM world back LTE, Sprint has been hemorrhaging wireless customers for years. On the equipment side, Cisco plunked down $3 billion for Starent Networks, a maker of enhanced packet core gateways for mobile networks that clearly sees LTE as the future. Shortly after, Cisco killed the WiMAX RAN business it acquired with Navini.
But Mobile WiMAX looks to have beaten LTE in terms of service rollout. Sprint and Clearwire turned up service in Baltimore in late 2008. As of May 2010, Clearwire has commercial WiMAX services available in 27 U.S. markets, covering more than 34 million points of presence (POP). Clearwire is offering the service on a wholesale basis to Sprint, Comcast and Time Warner Cable. By the end of 2010, Clearwire will have built out a WiMAX network that spans all major U.S. markets and covers 120 million POPs.
The WiMAX community plans a significant upgrade to the technology. The IEEE 802.16m standard will be much faster than its predecessor, 802.16e. The goal is for the new WiMAX standard to deliver average downlink speeds of more than 100Mbps to users. In contrast, Sprint's initial Xohm WiMAX offering delivered downlink speeds ranging between 3.7M to 5Mbps.
Meanwhile, Verizon expects to be offering its 4G Long-Term Evolution (LTE) services commercially in 25 to 30 major U.S. markets. It plans to double its total number of 4G markets by the early part of 2012. By the end of 2013, the company plans to have its entire current 3G footprint covered by its 4G technology and to expand its 4G services into areas that don't currently have 3G.
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