Wi-Fi and LTE-LAA coexistence problems, challenges and features in 5GHz unlicensed bandwidth

Year 2019, Volume: 23 Issue: 6, 1242 - 1255, 01.12.2019

Maqsood Sulaimani , Seçkin Arı

https://doi.org/10.16984/saufenbilder.557409

Abstract

The
demand for high data rate and stable Quality of Service (QoS) from cellular
networks’ subscribers is a huge challenge for cellular operators. To overcome
this issue (providing high data rate and stable QoS) it requires more
bandwidth. The lack of licensed bandwidth and also its high cost make it hard
for operators to overcome this issue. To find a fair solution and expand the
capacity of cellular networks, operators started deployment of Long Term
Evolution (LTE) in unlicensed bandwidth, exactly utilizing 5GHz unlicensed
bandwidth in small cell scenarios. The extension of LTE to the 5GHz unlicensed
bandwidth where it is already in used by Wi-Fi will create huge coexistence
problems between Wi-Fi and LTE. It results from that Wi-Fi and LTE have
different channel access mechanisms. This paper presents the channel access
mechanisms of Wi-Fi and LTE-Licensed Assisted Access (LTE-LAA), coexistence problems,
challenges, privileges, coexistence features of LTE and Wi-Fi and Finally, we
conducted the simulation for LAA based on Listen Before Talk (LBT) mechanism and Wi-Fi to find that how LAA with
LBT mechanism is friendly to the Wi-Fi networks when they share the same
bandwidth. The simulation results illustrate that LAA based on LBT channel
access mechanism by alone cannot bring a fair coexistence between these two
technologies, it needs further improvement.  

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Keywords

LTE, LTE-LAA, Wi-Fi, Coexistence, LBT, CSMA/CA, performance

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