No person, firm or corporation shall, either as principal or agent, engage in the business of conducting or maintaining or soliciting business for any security patrol system or security patrol service without first obtaining a security patrol license from the city to do so. No person shall be employed as a watchman, guard or security patrol officer by a person, firm or corporation engaged in the security patrol business without first obtaining an employee permit from the city to do so. Any person, firm or corporation, either as principal or agent, engaging in the bus patrol service or system at the time of the enactment of the ordinance codified in this chapter, and any person employed as a watchman, guard or security patrol officer by a person, firm or corporation engaged in the security control business at the time of the enactment of the ordinance codified in this chapter, shall have a period of thirty days from the date of enactment of the ordinance codified in this chapter, to procure the security patrol license and employee permits required by this section.