A new model for the simulation of the LTE-EPC data plane

Nicola Baldo, Manuel Requena, Jaume Nin, Marco Miozzo

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The LENA project (LTE/EPC Network Simulator)

• CTTC working with Ubiquisys, the leading femtocellmanufacturer

• Objective: develop a common platform for LTE femto/macro cell vendors to evaluate their different solutions• e.g., make sure that large and small cells from different

vendors will work harmoniously before they are deployed• Open Source to foster adoption and contributions• Based on ns-3

• Use case: LTE-based Self Organized Networks• Need to test SONs algorithms before deployment• Ubiquisys made extensive use of simulation to design its first

generation of WCDMA intelligent femtocells• Product–oriented:

• Real-world interfaces for SON algorithms• FemtoForum MAC Scheduler API specification• Allow testing real code in the simulator

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Previous work

• LTE PHY and MAC• FemtoForum Scheduler API• Adaptive Modulation and

Coding• Inter-cell interference

• Only saturation traffic model• No interworking with IP stack• No support for realistic

applications

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The new LTE-EPC model

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LTE-EPC data plane protocol stack

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Downlink data flow

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Uplink data flow

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LTENetDevice

model

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RLC models

• RLC Unacknowledged Mode (UM)– SDU Segmentation– SDU Concatenation– SDU Reassembly– Data PDU loss detection and SDU Discard

• RLC Acknowledge Mode (RLC)– SDU Segmentation– SDU Concatenation– SDU Reassembly– Status PDUs– Data PDU retransmission

10Execution time performance

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Other new LENA features (not in the paper)

• Buildings model– Presence of buildings in the topology– Propagation loss models

• Different loss for indoor/outdoor cases• different shadowing• External & internal wall loss

• Antenna models– Isotropic antenna model– Cosine antenna model– Parabolic antenna model

• LTE PHY error model– Mutual Information Effective SINR Mapping (MIESM)– Block error curves from link-level simulations

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Example: dual stripe scenario

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Hexagonal cell grid topology

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Work in progress

• MIMO model• HARQ• RRC • X2

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Check it out!

http://iptechwiki.cttc.es/LTE-EPC_Network_Simulator_(LENA)