dense ran: handling interference in a dense city …€¦ · flexi zone controller. flexi zone ap...
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Dense RAN: Handling Interference in a Dense City EnvironmentGTI workshop, TokyoDr. Phil Fleming, Head of Radio Technology & Engineering
TD-
2 © Nokia Siemens Networks 2011
NSN Concepts for High Density City Environment
• Light to medium Add more macrocell capacity• Medium to heavy Macros and picocell clusters over ethernet• Heavy++ load Dense RAN using Macros/picos and PicoRRH over fiber w/BB pooling to eliminate the cell edge
Stadiums are challenging venues that test wireless data systems
The solutions depend on the penetration of smartphones and the density of the crowd
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Fiber + picoRRH
DistributedSchedulerPacket-based Coordination
Spectrum of Architectures to Supplement Macrocells and Eliminate the Cell Edge
Offload
AP
Core
Controller
AP
Transport
AP
AP
Low TCO Indoor SolutionEthernet
Enterprise LAN
EPCInternet
WAN & ent. Internet
Flexi Zone controller
Flexi Zone AP 6
Looking SW from Macro antenna on 200N
FZ AP 1 NLOS
FZ AP 7 NLOS
FZ AP 1 NLOS
FZ AP 1 NLOS
FZ AP 8 NLOS
FZ AP 1 NLOS
Offload
AP
Core
Controller
AP
Transport
AP
APOffload
AP
Core
Controller
AP
Transport
AP
AP
IP Backhaul;Delay Tolerant >10msIncluding Wireless
AP-Cluster 12-15
IP Backhaul;In-building/EnterpriseWiring, Network (CAT5, Switching/Routing)Latency ~10ms
Urban Street Indoor
increasing user density
Dense RAN
Fiber-Interconnect Dense AP/RRH<1ms latency
Ethernet/Wireless BH + picoAP
Centralized schedulerJoint Receiver/Transmitter
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Dense RAN solutions
64 cells in a 300x200 m2 stadium 1000 cells/km2!
• Stadiums have the densest population of smart phones in the world• Up to 100,000 fans sending videos to friends and watching highlights on Youtube• Many small (unobtrusive) low power cells over fiber or Ethernet
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The user’s signal quality degrades as more cells are added to the stadium
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The user’s signal quality degrades as more cells are added to the stadium
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The Interference Dimensionality Problem
Cell edge throughput decreases with more
cells
Stadium capacity increases with more
cells but not proportionally
Dense user population Dense cellsMore interference and More interferers!Higher Interference Dimension
20 MHz TD-LTE
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Comparison of Stadium Dense RAN Uplink Methods
Cell-
edge
elim
inat
ed!
Capacity scales with Dense RAN methods
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Elimination of the cell edge on the uplink
Thro
ughp
ut in
Mbp
s
Independent cellsIndependent cells CoMP (Static)CoMP (Static)
CoMP (Dynamic)CoMP (Dynamic) CoMP (Dynamic, Advanced Joint Rx.)CoMP (Dynamic, Advanced Joint Rx.)Many users have Tput <
0.5 Mbps
All users have Tput >
1.5 Mbps
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Downlink without Dense RAN
In 32-sector stadium system, the low throughput users cluster on the cell edge
High throughput users
Low throughput users
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Downlink with Dense RAN
Bottom 10% throughput users’ location distribution
Dense RAN transmission algorithms leverage the reciprocity of TD-LTEFewer low throughput users that are clustered in the outer rim of the CoMP setDense RAN will use overlapping CoMP sets to eliminate the cell-edge
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Downlink Dense RAN Throughput comparison
8 cells
16 cells
32 cells
64 cells
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Summary
NSN has Dense RAN solutions for both UL and DL• Pico clusters using advanced joint reception and transmission algorithms • Advanced architectures enabling overlapping CoMP groups of cells
Dense RAN Solutions designed for and evaluated in the most challenging ultra-dense venues in the world: Stadiums
Dense RAN efficiently handles high interference venues by eliminating the cell edge using overlapping clusters