open source 4g radio
TRANSCRIPT
Open-source 4G radio:It's time to start WiMAX and LTE hacking
Alexander Chemeris
Alexander Chemeris @chemeris [email protected]
Mobile WiMAX● Standardized by WiMAX Forum● Air interface - a profile of IEEE 802.16-
2009 OFDMA mode.● IEEE 802.16 — http://goo.gl/SUpqE● WiMAX profies — http://goo.gl/k1xjK
● Deployed release 1.5.● Core network - IETF protocols
Alexander Chemeris @chemeris [email protected]
Mobile WiMAX vs LTE
Mobile WiMAX ● developed by Internet Providers community● «evolution of WiFi»● appeared first
LTE● developed by telecom community● based on WiMAX ideas● but with other patents
Alexander Chemeris @chemeris [email protected]
Orthogonal frequency-division multiplexing (OFDM)
Refer to "Intuitive Guide to Principles of Communications"Tutorial 22 - Orthogonal Frequency Division Multiplex (OFDM, DMT):http://www.complextoreal.com/chapters/ofdm2.
Alexander Chemeris @chemeris [email protected]
OFDMA (frequency)
user 1
combined
user 4
user 3
user 2
frequency
Alexander Chemeris @chemeris [email protected]
OFDMA (time and frequency)
Alexander Chemeris @chemeris [email protected]
TDD and FDD
DL
UL
DL UL DL UL
Frequency DivisionDuplexing (FDD)
Time DivisionDuplexing (FDD)
default
radioframe
radioframe
radioframe
DL
UL
radioframe
time
freq
uen c
y
Alexander Chemeris @chemeris [email protected]
WiMAX frame
Alexander Chemeris @chemeris [email protected]
WiMAX frame
Alexander Chemeris @chemeris [email protected]
OFDMA frame
Alexander Chemeris @chemeris [email protected]
Mobile WiMAX● Many bands, mostly 2 GHz — 5 GHz● Scalable bandwidth: 1.5 MHz — 20 MHz● Usually TDD● Supports various MIMO and beam-forming
Alexander Chemeris @chemeris [email protected]
LTE differences● Uplink uses SC-FDMA for power efficiency● Power efficient synchronization● More dynamic parameters at PHY level● Hierarchical telecom-like protocol
For details: http://goo.gl/HAAgm
Alexander Chemeris @chemeris [email protected]
wimax-scanner ● Mobile WiMAX receiver● LGPL● Matlab code for broadcast decoding● Wireshark for MAC layer decoding
http://code.google.com/p/wimax-scanner
Alexander Chemeris @chemeris [email protected]
wimax-scanner ToDo● Port to C(++)● Improve algorithms in Matlab● More WiMAX recordings● More WiMAX recordings in MIMO mode● Transmitter side
http://code.google.com/p/wimax-scanner
Alexander Chemeris @chemeris [email protected]
Other open-source 3G&4G
UMTS and LTE implementations in GPL
http://www.openairinterface.org
● Closed style development● Targets academia● Hackers should engage