Algorithms for Resource Allocation in HetNet Jianwei Liu Clemson University

What is used currently Only in single cellular network. Associate with the best signal BS.

Paper 1-GPF

Generalized Proportional Fair: Note there assumptions: Rate is related to Qa, which is the number of users connecting to the same BS. All users must be admitted. Every user can only connect to exactly one BS. (It’s not HetNet) User can consume whatever is allocated to him/her. Only consider downlink.

Paper 1-GPF GPF 1:

Paper 1-GPF GPF 2:

Paper 1-GPF Generalized Proportional Fair Contributions: Proved GPF1 is NP-hard(by mapping to 3d matching problem) Proved GPF 1 is inapproximable. Provided an optimal offline algorithm for GPF2. Provided an local search algorithm, but may not work for some cases. Provided Greedy algorithms. Greedy-0 and Greedy-k.

Paper 2-Mota MOTA assumptions: Users can use interfaces simultaneously. (run multiple applications) But, one application can only use one interface/RAT. For each RAT, one user can only choose one carrier. Every application has a weight. It depends on application class. It kind of reflects the bandwidth demand of one application.

Paper 2-Mota

Algorithm:

Paper 3-Minimize Delay Problem Formulation: Try to minimize the sum-delay in downlink of cellular networks Show it can be linearized by using HST embedding. The solved problem is kind of changed.

Paper 3-Minimize Delay Problem Formulation:

What Future network will look like Motivations: From the application perspective: M2M, Internet of Things, various types of applications Some of them are real-time, need QoS guarantee CVT applications, delay requirement From the network perspective: Picocell, femtocell, relay based offloading, SDN based offloading. (will add citations) Problem of QoS in the LTE cellular system ( service-in-lte-long-form.pdf)

What Future network will look like Motivations: From the application perspective: M2M, Internet of Things, various types of applications Some of them are real-time, need QoS guarantee CVT applications, delay requirement From the network perspective: Picocell, femtocell, relay based offloading, SDN based offloading, WiFi offloading, HetNet, cooperation of different carriers. (will add citations) Problem of QoS in the LTE cellular system ( service-in-lte-long-form.pdf)

What Future network will look like

Assumptions 1) The traffic we deal with are all demand-aware traffic. 2) We assume every user can use up to C inter interfaces. For example, we limit the C inter to 3 in our simulation. 4) Every application will choose or be classified to an application class (ACS), which has known delay from the cellular gateway. We represent the application classes as T 1,..., T t,..., T c. 5) The rate of application i using interface j depends on the location p where the user operates the application i is, and the SINR at p. R(i,j,f) = log(1 + SINR(p)) * bandwidth allocated The total rate of one application get based on assignment f is: R(i, f) = j R(i, j, f )

Rationale Delays need to be guaranteed Some application demands can be known, like videos Try to maximize spectral efficiency. Try to balance the load of BSs. (why, congestion, assume they are well distributed, will increase the chance of being admitted). Try to Minimize the averaged number of interfaces used. Or limit it to a constant. –Good signal – use just one interface –Bad signal – use multiple

Problem Formulation

Proposed Resource Allocation Algorithm 1.Every application sends request to BS every T_interval 2.BS will calculate the estimated congestion ratio. 3.Central Resource Allocation Server (RAS) get reports from all the BSs. (The reports contains both congestion ratio, and all the link status, and application requests) 4. RAS finds a proper average load ratio Avg_ratio for this T_interval 5. RAS design a scheduling scheme, and send them back to BSs If BS’s Est_ratio > Avg_ratio, rank users based on their SINR in the list of every BS. Notify (Est_ratio – Avg_ratio) + c% users offload their traffic to a second interface. The offloading will be simulated, and converge to a solution with certain threshold