What are the well-known communication companies in Shanghai? detailed

Shanghai Haida Communication Company, Shanghai Yida Communication Company, Shanghai Satellite Communication Company, Shanyou Communication Company, Wanxiang Communication Company, Shanghai Guomai Cluster Communication Company, Lianlun Communication Company, Shanghai Jielun Communication Company, Huatong Communication Co., Ltd., Huaxia Communication Co., Ltd., Shanghai Hope Optical Communication Co., Ltd. and Lexus Communication Co., Ltd. . . .