# ITFDS: Channel-Aware Integrated Time and Frequency-Based Downlink LTE Scheduling in MANET
## 1 Introduction
OFDMA [22] was used for allocating resources in which the downlink channel in the period domain is separated into frames of 10 ms and every channel contains 10 subframes of 1 ms. The scheduling algorithms were classified as QoS-aware scheduling and QoS-unaware scheduling [23]. The maximum throughput scheduling leads the aggregation throughput according to the CQI to achieve high data RTE in the channel [24]. In fair scheduling algorithms, resource allocation would take placed by considering both the available data rate and the achieved data rate. It shows the trade-off between throughput and fairness [25]. A mechanism [26] accepting the concept [27] introduces a utility function for improving the fairness index. Scheduling based on optimal DRX embedded in the same MAC scheduler was given in [16]. Resource allocation for QoS-aware channels was emphasized in [28]. Throughput and delay can be calculated together in real-time and non-real-time allocations [29]. Depending upon the delay and channel quality, packets are scheduled to the physical layer for transmission [30]. LTE networks provide very high data rates for downlink transmissions so that they can transmit large amounts of data with packet optimization to users [31]. The base station is responsible for allocating resources to users' equipment for LTE downlink transmission [32]. The downlink scheduling with delay-related weighted technique using LTE cellular networks provides better tradeoff of fairness and throughput between users in dissimilar traffic situations [33]. Dynamic packet scheduling is the main element of LTE network aiming to increase throughput and QoS to end users. Because of resource limitations, the queuing-based monitoring technique was used in downlink LTE communication to increase throughput and fairness among users [34]. The energy-based spectrum resources are optimized using the green cellular system to acquire the channel data for transmitting packets through base station [35]. The optimized resources are utilized to provide QoS at the downlink scheduling. A packet prediction technique was implemented in the eNodeB for optimization [36]. A channel-related feedback method [36] using the adaptive feedback threshold was generated to minimize the overhead while transmitting packets [37]. The system performance was measured using the downlink packet scheduling procedure [38]. The architecture of LTE network by 3 GPP is shown in Figure 1.  
3 GPP is the universal mobile communication standards organization that works to provide the latest technology in order to reduce the traffic and identified the LTE standard release 8. LTE contains two subnetworks called the evolved-universal terrestrial radio access network (E-UTRAN) and evolved package core (EPC). E-UTRAN was introduced within LTE and it act as the interface between user equipment (UE) and eNodeB. LTE communicates by orthogonal frequency division multiplex (OFDM) with huge amount of orthogonal subcarrier signals to carry data on several parallel data stream and channels. The time domain has a 10 ms radio resource in a frame and 10 subframes of 1 ms length for each. In the other hand, the frequency domain has multiple subcarriers with 15 KHz bandwidth for each. Around 12 subcarriers from the frequency domain and 0.5 ms from time domain is regarded as a resource block (RB), which is allocated to users every 1 ms called transition time interval (TTI). Figure 1: Architecture of LTE - 3 GPP. Figure 1 illustrates the LTE, which is divided into two parts, namely EPC and E-UTRAN. E-UTRAN has a flat architecture consisting of two eNodeB nodes, which will do all processing through an air interface protocol. It is an independent entity. One eNodeB is connected with the multiple eNodeB through interface X. The eNodeB is connected to the serving gateway (S-GW) through interface S1-U. Similarly, the serving gateway is connected to MME through interface S11. MME is responsible for control plane signaling in which the serving gate is responsible for the control plane or actual dataflow.