Coordinated Allocation of Radio Resources to Wi-Fi and Cellular Technologies in Shared Unlicensed Frequencies

Abstract

Wireless connectivity is essential for industrial production processes and workflow management. Moreover, the connectivity requirements of industrial devices, which are usually long-term investments, are diverse and require different radio interfaces. In this regard, the 3GPP has studied how to support heterogeneous radio access technologies (RATs) such as Wi-Fi and unlicensed cellular technologies in 5G core networks. In some cases, these technologies coexist in the same spectrum. Dynamic spectrum sharing (DSS), which has already been proven to increase spectrum efficiency in licensed bands, can also be applied to this scenario. In this paper, we propose two solutions for mobile network operators (MNOs) or service providers to dynamically divide (multiplex) the radio resources of a shared channel between a Wi-Fi basic service set (BSS) and one or several carriers of scheduled wireless networks, such as cellular technologies, with a configurable level of sharing granularity. These solutions do not require modifications to the current commercial off-the-shelf (COTS) end devices. We adapt the existing IEEE 802.11 procedures to notify the Wi-Fi stations that they must share channels with different access networks. We demonstrate that our dynamic sharing proposals are also advantageous over direct coexistence and evaluate each of them quantitatively and qualitatively to determine when one or the other is preferable. The evaluation is particularized for IEEE 802.11ac and long-term evolution (LTE) license assisted access (LAA), but the solutions can be easily extended to 5G new radio-unlicensed (5G NR-U) or to any other wireless technology in which the network side schedules end device transmissions.

Developing capacity sharing strategy for vehicular networks with integrated use of licensed and unlicensed spectrum

“…Let's use the IEEE 802.11n protocol that operates on the 5 GHz range with orthogonal unlicensed channels as well as an RTS/CTS protocol. The key simulation parameters are summarized in Table 1, which are similar to the licensed spectrum parameters in [27] and unlicensed spectrum and WiFi parameters in [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32]. Fig.…”

“…This paper considers a radio resource allocation strategy, keeps track of the available radio resource to be used for the transmission i.e., the vehicles are assumed to use the licensed radio sources, and in case they are not available due to the increased demands for the licensed sources, the vehicles will share the unlicensed radio resources with WiFi users. As in [30,30], let's assume that Wi-Fi users can generally start transmitting at any point after a Carrier-sense multiple access with collision avoidance (CSMA/CA) procedure. Thus, WiFi devices notify the controller of their intention to start transmission with information on the start and occupancy times of the channels.…”

Is the edge really necessary for drone computing offloading? An experimental assessment in carrier‐grade 5G operator networks

“…Nevertheless, these results would not be achievable in a more open general setup, in which multiple external heterogeneous devices would coexist within the same license-free channel. Wi-Fi transmissions employing packet aggregation techniques to share the channel more efficiently can take up to 32.767 ms. 40 Therefore, delays may be much less predictable in reality than in tightly controlled laboratory environments. Moreover, cellular networks have additional capabilities over a Wi-Fi access network beyond transmission scheduling, such as improved adaptive modulations.…”

“…Moreover, even if the end devices of the network are not configured to use long buffers, they can still experience long delays due to the behaviour of other wireless devices within the same license‐free channel. Indeed, Wi‐Fi devices may use of the channel for up to 32.767 ms 40 . In addition, cellular networks adapt their modulation and coding rate better to dynamic channel conditions and are not subject to the strict constraints of industrial, scientific, and medical (ISM) bands.…”

Towards Trusted and Accountable Win-Win SDWN Platform for Trading Wi-Fi Network Access

“…Candal-Ventureira et al [7] introduced and evaluated two solutions for wireless network operators to dynamically divide the radio resources of a shared channel between Wi-Fi and cellular technologies to enhance spectrum efficiency without requiring modifications to current commercial off-the-shelf (COTS) end devices. Their approach avoids competition between technologies sharing the medium by allocating alternate time slots.…”