## 1 Introduction
Our previous work [21] researched the RWTA methods under the scenario that quantum signals and classical signals coexist in C-band in which 2, 4, and 6 wavelengths are allocated for QKCh and MBCh. Meanwhile, excluding the four wavelength channels reserved as guard band for QKCh and MBCh, 32, 28, and 24 allocated wavelengths remain for TDCh. There is also research to explore using O-band and C-band for carrying quantum signals and classical signals, respectively [14; 15]. As described above, integrating QKD into optical networks can avoid the high cost of establishing dedicated QKD networks, which is a feasible and effective way to accommodate many more users in secure data communication. Some hybrid networking architectures based on trusted repeaters and weakly trusted repeaters have been proposed to overcome the transmission distance limit of quantum signals. Additionally, QKD-enabled optical network architecture supported by software-defined networking (SDN) has been demonstrated. Under the architecture, the unified construction of three types of channels mentioned above was discussed in detail [25; 26]. Since wavelength resources in an optical fiber are limited, only a few wavelengths can be allocated to construct QKCh and MBCh. A timeslot slicing scheme based on optical time-division multiplexing (OTDM) technology can be adopted to construct QKCh and MBCh for efficient wavelength utilization. Due to the introduction of OTDM technology, resource allocation in QKD-enabled optical networks includes routing, wavelength, and timeslot assignment (RWTA) for key configuration processes in addition to traditional routing and wavelength assignment (RWA) for data transmission. Reasonable scheduling and efficient utilization of those multi-dimensional resources, i.e., wavelengths and time-slots, is a very important topic in QKD optical networks. The RWTA methods in traditional OTDM optical networks mainly solve the problem of RWTA for the traditional data channel. For example, Ref. [22] studies how to determine the RWTA that meets the given request with a specified bandwidth. In the QKD-ON, the RWTA method is not only oriented to classical data channels, but also to quantum-key channels and measurable-basis channels. Apart from that, to improve the security of the encrypted data when adopting the advanced encryption standard (AES), the secure key for a TDCh should be updated periodically. The RWTA algorithm in Ref. [21] was designed to allocate wavelength and time-slot resources for the three types of channels considering different security levels. Ref. [21] also gave the feasibility of adopting OTDM to allocate multiple QKChs and TDChs over the same wavelength. The OTDM in QKDN is realized based on the traditional optical switches which support fast switching. Ref. [27] proposed the RWTA problem for efficient quantum key pool construction over WDM networks combining with quantum key pool (QKP) technique. However, they did not consider the wavelength-time-slot fragmentation caused by the constraints of wavelength consistency and time-slot continuity which this paper considers for improving the use of wavelength resources. In this paper, we focus on the designing of resource allocation schemes for those three kinds of channels mentioned above. The main contributions in this work are as follows: (1) a time-window-based security orchestration (TW-SO) strategy for key updating is proposed to provide customized policies for services with different security levels. (2) Several indices  
Figure 1: (a) Point-to-point quantum key distribution (QKD) system; (b) Wavelength allocation for different channels on C-band. to describe the resource states are designed, including time continuous compactness and relative-loss of time continuous compactness. (3) The ReLoss-TCC (relative loss of time continuous compactness)-based multi-dimensional RWTA strategy is proposed while accommodating services with security requirements in QKD optical networks.