Encoding and transmission of orthogonally optical label switching using DQPSK payload and MD-RZ label
Encoding and transmission of orthogonally optical label switching using DQPSK payload and MD-RZ label
复制标题
DOI：
10.1117/12.756289
复制
发表时间：
2007-11
期刊：
影响因子：
--
通讯作者：
Yufeng Shao;S. Wen;Lin Chen;Yaoqiang Xiao
中科院分区：
文献类型：
--
作者：
Yufeng Shao;S. Wen;Lin Chen;Yaoqiang Xiao
光标签交换（OLS）被认为是一种在光层透明地路由和转发IP分组的有效技术。在标签交换系统中，正交调制技术具有频谱利用率高等优点。一个示例是幅移键控（ASK）标签和差分相移键控（DPSK）有效载荷的组合。然而，差分正交相移键控（DQPSK）的有效载荷还没有被用于光标签交换系统。本文首次提出并实现了一种基于修正归零码（MD-RZ）和DQPSK相结合的光标签交换方案。发射机由两个相位调制器（PM）和一个双臂LiNbO 3调制器（LN-MOD）级联而成。信号首先由两个PM进行相位调制。MD-RZ标签然后被随后的LN-MOD压印。MD-RZ标签的占空比和消光比是可调的。DQPSK有效载荷可用于20 Gbit/s光标签交换系统，每符号2比特调制/解调。在网络内，标签信息被读取、处理和更新，这一过程称为标签交换，直到突发到达期望的出口边缘节点。预计使用平衡检测将提高有效载荷的性能。分析了20 Gbit/s DQPSK有效载荷与2.5Gb/s MD-RZ-ASK标签的传输性能。DQPSK有效载荷的MD-RZ标记已被证明是用于实现OLS系统的有希望的候选者。
Optical label switching (OLS) has been regarded as an efficient technique to route and forward IP packets transparently in the optical layer. In label switching system, orthogonal modulation has shown some advantages, such as its high spectral efficiency. One example is the combination of amplitude-shift-keying (ASK) label and differential phase-shift-keying (DPSK) payload. However, differential quadrature phase-shift-keying (DQPSK) payload has not been used in optical label switching system yet. In this letter, we propose and demonstrate a novel optical label switching scheme by the combination modified return zero (MD-RZ) and DQPSK for the first time. The transmitter is set up by cascading two phase modulators (PM) and one dual-arm LiNbO3 modulator (LN-MOD). The signal is first phase modulated by two PMs. The MD-RZ label is then impressed by the subsequent LN-MOD. Duty cycle and extinction ratio of the MD-RZ labels are tunable. The DQPSK payload can be used in a 20Gbit/s optical label switching system, with 2-bit per symbol modulation/demodulation. Within the network, the label information is read, processed and updated, a process known as label switching, until the burst reaches the desired egress edge node. The use of balanced detection is expected to improve performance for the payload. The transmission performance of 20Gbit/s DQPSK payload with 2.5Gb/s MD-RZ-ASK label is also analysed. MD-RZ labeling of a DQPSK payload has been shown to be a promising candidate for the implementation of OLS system.