LTE vs WIMAX by alifahnuha

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									A Comparison of Two
Fourth Generation Technologies:
WiMAX and 3GPP-LTE

Jacob Scheim
December 2006




                      White Paper
1      Introduction
Modern wireless wide area networks (WWAN) and wireless metropolitan area networks
(MAN) are under extensive investigation in recent years with a view to progressing
towards 4th generation (4G) public wireless networks. The intensive standardization
activity, currently in its final stages, may be considered as a major step towards 4G.
One well known example of this standardization effort is the IEEE 802.16e–2005
standard for fixed and mobile broadband wireless access (Mobile WiMAX). Early
systems based on this standard are expected to be deployed starting from 2007.

A parallel standardization effort is the evolved UMTS terrestrial radio access network
(E-UTRAN) — also known as 3GPP Long Term Evolution (3GPP-LTE) — launched by the
3rd generation standardization body (3GPP). This standardization activity has recently
moved on to a working item phase and is expected to conclude during 2007. Similar to
the IEEE 802.16e-2005 standard, 3GPP-LTE radio access is expected to be based on
OFDMA.

These standards provide the foundation for constructing networks for mobile broadband
wireless access and therefore are considered as precursors to 4G. In addition, there are
also other OFDM/A based research activities, non-3GPP or WiMAX related, that are
targeting 4th generation wireless access networks.


2      Comparison
Table 1 below presents the key elements of a comparison between the Mobile WiMAX
and 3GPP-LTE standards as they converge to 4G broadband wireless access systems.
This comparison focuses mainly on the physical layer aspects of the radio access
technology of these two standards.

                       Table 1. Comparison of 3GPP-LTE and IEEE 802.16e
                                    Mobile WiMAX                        3GPP-LTE
       Aspect
                                 (IEEE802.16e-2005)                    (E-UTRAN)
 Core network            WiMAX Forum™ All-IP network         UTRAN moving towards All-IP
                                                             Evolved UTRA CN with IMS
 Access technology:
 Downlink (DL)           OFDMA                               OFDMA
 Uplink (UL)             OFDMA                               SC-FDMA
                                                             Existing and new frequency
                         2.3-2.4GHz, 2.496-2.69GHz,
 Frequency band                                              bands
                         3.3-3.8GHz
                                                             (~2GHz)
 Bit-rate/Site:
 DL                      75Mbps (MIMO 2TX 2RX)               100Mbps (MIMO 2TX 2RX)
 UL                      25Mbps                              50Mbps
 Channel bandwidth       5, 8.75, 10MHz                      1.25-20MHz
 Cell radius             2-7Km                               5Km
                                                             >200 users @ 5MHz
 Cell capacity           100-200 users
                                                             >400 users for larger BW
 Spectral efficiency     3.75[bits/sec/Hz]                   5[bits/sec/Hz]




A Comparison of Two Fourth Generation Technologies: WiMAX and 3GPP-LTE                     -2-
                                 Mobile WiMAX                         3GPP-LTE
         Aspect
                              (IEEE802.16e-2005)                     (E-UTRAN)
 Mobility:
 Speed                 Up to 120Km/H                        Up to 250Km/H
 Handovers             Optimized hard handovers supported   Inter-cell soft handovers
                                                            supported

 Legacy                IEEE802.16a through 16d              GSM/GPRS/EGPRS/UMTS/HSPA
 MIMO:
 DL                    2Tx X 2Rx                            2Tx X 2Rx
 UL                    1Tx X NRx (Collaborative SM)         2Tx X 2Rx
 No. of code words     1                                    2
 Standardization       IEEE 802.16e-2005 PHY and MAC
                                                            RAN (PHY+MAC) + CN
 coverage              CN standardization in WiMAX forum™
                       New (work in process in WiMAX        Auto through existing
 Roaming framework
                       Forum™)                              GSM/UMTS

 Schedule forecast:
 Standard completed    2005                                 2007
 Initial Deployment    2007 through 2008                    2010
 Mass market           2009                                 2012



3        Conclusion
The parameters presented in Table 1 show that the Mobile WiMAX and 3GPP-LTE
standards are technically similar. However, in terms of market perspective the two
standards differ in terms of expected time to market and legacy. Although currently
less mature and widespread, Mobile WiMAX appears as if it will be first to market.
Significantly, WiMAX is already being tested (e.g., in Korea), whereas LTE has not
yet been standardized.

Following this observation, we may conclude that due to timeline benefits new service
providers as well as existing cable and DSL providers wishing to offer mobile services
are likely to select Mobile WiMAX as their technology for mobile broadband access. We
may also conclude that in the developed world major UMTS/HSPA service providers will
naturally evolve to 3GPP-LTE, whereas most CDMA2000 providers, as well as
GSM/EDGE providers in the developing world, will select Mobile WiMAX for mobile
broadband wireless access while providing service continuity over their legacy
networks.


4        References
[1] 3GPP TR 25.814 v7.0.0 3GPP; Technical Specification Group Radio Access Network;
    Physical layer aspects for evolved Universal Terrestrial Radio Access (UTRA).
[2] WiMAX Forum Mobile System Profile, V1.2.0 Sept. 2006.
[3] Source: WiMAX forum.

Mr. Jacob Scheim, Ph.D., Telephone: +972 9 971 7888,
Kobi.scheim@comsysmobile.com http://www.comsysmobile.com




A Comparison of Two Fourth Generation Technologies: WiMAX and 3GPP-LTE                  -3-

								
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