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Spectrum Licensing Instruments – Exclusive, Shared, or Common? K. Giridhar, IIT Madras giri@tenet.res.in November 20 , 2017. Our Focus sub-1GHz Bands for BWA. Premium spectrum Cash-Cow for GoI – especially sub-700MHz (>12K Crores per MHz) Exclusive licensing not advisable for BWA
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Spectrum Licensing Instruments – Exclusive, Shared, or Common?K. Giridhar, IIT Madrasgiri@tenet.res.inNovember 20, 2017
Our Focus sub-1GHz Bands for BWA • Premium spectrum • Cash-Cow for GoI – especially sub-700MHz (>12K Crores per MHz) • Exclusive licensing not advisablefor BWA • Too little to carve-up for 6 or even 4 operators! • IoT and M-M cannot be driving the use-case when reliable, ubiquitous, basic BWA is not available to a large part of the Indian population • Common licensing may not utilize spectrum wisely! • Also, QoS and coverage guarantees cannot be given • Shared licensing with thoughtful sharing is the key! • With technology to ensure “fairness of sharing” can be monitored
What is Shared in Cellular Networks Today ? • Sharing available today commercially for • Tower-sharing • Inter-circle roaming • Intra-circle roaming – “spectrum sharing” within same circle • Sharing studies have also been done for • Indoor base-station sharing (CEWiT) by multiple operators • Licensed Shared Access (LSA) – by Ericsson, Qualcomm, & Red • Orthogonal sharing of spectrum non-overlapping time or frequency slices • CBRS type deployment ? • Many research papers available on • Spectrum pooling, Cognitive radio based Secondary usage, etc • Non-orthogonal multiple access – for uplink users of same operator • We propose Licensed Shared Simultaneous Access (LSSA)
Licensed Shared Simultaneous Access • MOSSSAIC • Multi Operator Simultaneously Shared Synchronized Air Interface for Communications • 4 operator MOSSSAIC has been developed by IITM (6 also possible) • SSSB • Simultaneously Shared SynchronisedBand: 40MHz TDD in TV-UHF Band • Contiguous, fixed, pan-India band • More such TDD bands could be released once MOSSSAIC is successful
Why Focus on sub-1GHz Bands for LSSA ? • Premium Beach-front Spectrum! • By sharing, can we support broad-band access? • In addition to IoT and M-to-M, ubiquitous BWA possible with sharing! • Aim of LSSA: to make 40MHz appear “effectively” like 160MHz or more • Excellent coverage possible (with simple towers & antennas) • But, MIMO not effective in UHF bands • LSSA can be viewed as a simpler form of distributed (network) MIMO • Advanced signal processing (baseband algorithms) needed
LSSA (MOSSSAIC) –Advantage Simultaneous spectrum sharing by 4 to 6 operators can be great! • Significantly lower spectrum cost per operator • Low equipment cost per operator • Much higher throughputs/sq.km compared to single-operator network • Especially, much better uplink rates possible • Superior support for ultra-reliable and emergency communications • Enhanced QoS support
MOSSSAIC Throughput Simulation -- Example No of drops = 10 Channel averages = 10 per drop UEs per Sector = 30 No of Operators = 4 Bandwidth = 40 MHz Results are with “dumb” Round-Robin Scheduler
Summary -- Why Simultaneous Sharing? Why MOSSSAIC? • Can spur innovation in India at various levels • Core SEPs, algos, and designs will be Indian; use FRAND to get 3GPP IPs • Less costly electronics; USP is in baseband signal processing • Fabless semi-C start-ups, UHF antenna/RF companies can participate • Can leverage learnings from 4G-LTE available in Indian telecom industry • Can build ubiquitous (6G?) underlay network for India! • 5G cellular and 802.11ax systems can be the overlay to this at hotspots! • Indian telecom operators will learn to work together • Business un-usual!