1,577 research outputs found
Proportional Fair RAT Aggregation in HetNets
Heterogeneity in wireless network architectures (i.e., the coexistence of 3G,
LTE, 5G, WiFi, etc.) has become a key component of current and future
generation cellular networks. Simultaneous aggregation of each client's traffic
across multiple such radio access technologies (RATs) / base stations (BSs) can
significantly increase the system throughput, and has become an important
feature of cellular standards on multi-RAT integration. Distributed algorithms
that can realize the full potential of this aggregation are thus of great
importance to operators. In this paper, we study the problem of resource
allocation for multi-RAT traffic aggregation in HetNets (heterogeneous
networks). Our goal is to ensure that the resources at each BS are allocated so
that the aggregate throughput achieved by each client across its RATs satisfies
a proportional fairness (PF) criterion. In particular, we provide a simple
distributed algorithm for resource allocation at each BS that extends the PF
allocation algorithm for a single BS. Despite its simplicity and lack of
coordination across the BSs, we show that our algorithm converges to the
desired PF solution and provide (tight) bounds on its convergence speed. We
also study the characteristics of the optimal solution and use its properties
to prove the optimality of our algorithm's outcomes.Comment: Extended version of the 31st International Teletraffic Congress (ITC
2019) conference pape
Optimal Traffic Splitting Policy in LTE-based Heterogeneous Network
Dual Connectivity (DC) is a technique proposed to address the problem of
increased handovers in heterogeneous networks. In DC, a foreground User
Equipment (UE) with multiple transceivers has a possibility to connect to a
Macro eNodeB (MeNB) and a Small cell eNodeB (SeNB) simultaneously. In downlink
split bearer architecture of DC, a data radio bearer at MeNB gets divided into
two; one part is forwarded to the SeNB through a non-ideal backhaul link to the
UE, and the other part is forwarded by the MeNB. This may lead to an increase
in the total delay at the UE since different packets corresponding to a single
transmission may incur varying amounts of delays in the two different paths.
Since the resources in the MeNB are shared by background legacy users and
foreground users, DC may increase the blocking probability of background users.
Moreover, single connectivity to the small cell may increase the blocking
probability of foreground users. Therefore, we target to minimize the average
delay of the system subject to a constraint on the blocking probability of
background and foreground users. The optimal policy is computed and observed to
contain a threshold structure. The variation of average system delay is studied
for changes in different system parameters.Comment: Conferenc
Opportunistic Third-Party Backhaul for Cellular Wireless Networks
With high capacity air interfaces and large numbers of small cells, backhaul
-- the wired connectivity to base stations -- is increasingly becoming the cost
driver in cellular wireless networks. One reason for the high cost of backhaul
is that capacity is often purchased on leased lines with guaranteed rates
provisioned to peak loads. In this paper, we present an alternate
\emph{opportunistic backhaul} model where third parties provide base stations
and backhaul connections and lease out excess capacity in their networks to the
cellular provider when available, presumably at significantly lower costs than
guaranteed connections. We describe a scalable architecture for such
deployments using open access femtocells, which are small plug-and-play base
stations that operate in the carrier's spectrum but can connect directly into
the third party provider's wired network. Within the proposed architecture, we
present a general user association optimization algorithm that enables the
cellular provider to dynamically determine which mobiles should be assigned to
the third-party femtocells based on the traffic demands, interference and
channel conditions and third-party access pricing. Although the optimization is
non-convex, the algorithm uses a computationally efficient method for finding
approximate solutions via dual decomposition. Simulations of the deployment
model based on actual base station locations are presented that show that large
capacity gains are achievable if adoption of third-party, open access
femtocells can reach even a small fraction of the current market penetration of
WiFi access points.Comment: 9 pages, 6 figure
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